Hi scuba--good to see you again It appears, like the last thread you and I went rounds on, that you have shown yourself capable of gaining other perspectives and chaning your mind:bravo

Much of what I have to say does not really apply to you anymore because you have changed your mind--but I think it adds a new perspective to teh discussion (and perhaps others are following along).
Full disclosure: I fully admit that one of the things I enjoy about
Disneyland Paris is that there is such a dramatically smaller number of EVCs and wheelchairs in the parks. It makes the parks much easier to navigate and means these types of arguments tend not to come up. I have no issue with EVCs at all, but I admit I enjoy a park which is not crammed with wheeled devices; just as I am sure those in such devices would enjoy not needing to use them.
Additional disclosure: I am a mother of two. I managed dozens of bus rides back to the resorts with a sleeping toddler or preschooler in my arms. It never occurred to me to expect someone to give up their seat to me--I always knew I had the option to wait for yet another bus if I did not want to stand and I certainly always knew the folding seats could need to be used at any time for an EVC. I have not ever been confiend to a wheelchair or EVC so I have no knowledge of what it is really like other than heresay and trying to put myself in other's shoes in my own mind.
I would assume (becuase in numerous posts he has never said otherwise) OP's daughter are typical, healthy kids. If so, at the age of nearly 4 the older one (and possibly even the younger one) is surely hopping out of her stroller when arriving at an attraction--much like OP describes the EVC users doing. One could ask WHY is the child in the stroller when she clearly does not need it? After all, we can probably all attest to having been rammed by careless (or downright malicious in some instances) parents pushing such strollers, and the strollers take up a lot of room on the busses (we are a weird family who enjoys figuring things out and happened to "calculate" about how many spaces per bus were being taken up by strollers that could have had a person standing there if the stroller were not along--we estiamtes an averge a 8-10 more people could have ridden each bus had there been no strollers on them

). Also, balancing all those stollers while also balancing a plethora of bags and a sleeping child on a bus leads to a dangerous situation for all of us around the "sherpa parent"

Yes, I have had a stroller land on DS's head when the parent lost their grip on it while maintaining their grip on their child. Often I have held a stroller for a parent so that the parent can better hold his/her child (safer for that child and those of us in range of the falling stroller).
The answer is pretty obvious isn't it? Your DD does not need to be in a stroller to handle walking shorter distances at all. But, at her age, the sheer amount of walking at WDW combined with the heat is just too much for her to handle. So, you bring along a stroller. For many with EVC or wheelchairs something similar may be happening.
I certainly think EVC/wheelchair abuse does happen. We once stayed next door to a family in which the three teens argued loudly every morning over who got to ride in the EVC that day

We also had two instances last trip where people in chairs/EVCs (one of each) came behind us in accessible fastpass lines and tried to push on pass to the front of the line (I have no idea how many people let them through before they got to us. In both cases we politely explained that as far as we understood they were supposed to wait with the rest of the line and we would certainly clarify with the next CM and apologize of we were wrong. One was sort of nice about it and seemed genuinely confused. The other had her husband keep ramming her chair into my ankles until we got to the fastpass check point while loudly telling me to move. At the point I politely asked the CM if we were supposed to allow chairs and EVC to pass through and she said no and stopped the people behind us to clarify. The poor CM was being yelled at by this person at the time that we rounded the corner

The amount of abuse that I have seen considering the number of chairs and EVCs in the parks and the number of trips I have taken is pretty small though. In such cases I feel angry with the abusers because it increases the amount of animosity legitmate users have to face from people like the OP (orgianlly when he wrote it), rather than feeling anger towards EVCD users in general.
I think "parent abuse" is much more rampant. On every trip I have seen a large number of school age kids riding in strollers--often kids whose parents admit they are not faced with any challenges, but just get tired easily from all that walking. As previously stated, strollers take up a lot of room on busses (and the stroller parking lots are really not adding to the beauty of the parks

) so maybe that is not right? I have also enountered, multiple times on every single trip parents who think the fact that they have little kids trumps everyone else (really funny at WDW where half of us do) meaning they use that as the reason why they should get to sit on the bus, why they should get to get out of line and reenter where they were (potty break), why they should get to move to the front of the parade viewing even though they did not get a spot ahead of time, and on and on and on.
My point is NOt to go on a rampage and say I think parents should not be given any consideration at WDW or that most stroller users are abusing the privelagge, etc.. My point is, that often the perspective is dramatically different from "inside" than as an outsider and often what seems reasonable to you seems annoying and demanding to others and there are those who abuse the consideration given to ANY group. Somehow, we all tend to notice those abusing their stauts in other groups (and then blame the entire group) more than we notice from within our own ranks (wether we are in EVCs, are parents, are Americans, are photographers, etc. This can pretty much apply to any group you can lump together). Disney does its best to accomidate everyone fairly. They even give some special perks to parents (child swap!) that no one else gets. Try to relax and work with the system and you will be much happier (and in your case right now I agree that renting a car is likely what you need to do).