Well, here is where opinions diverge.
As a guy going to the Fort for over 20 years, I see golf carts as an expensive convenience but not a necessity. IMO I can walk or bus for park transport in either Fort direction from October to May. During the warm summer months, I see the benefit.
So you want the alternative of a WET golf cart ride in the rain (with no rain tarps on a Disney cart) over a dry bus ride? And if it's raining at FW, it's likely raining in the parks that you just left.
Oh and if it's raining, stay under the bus depot shelter and wait for an internal bus - don't walk without ponchos, umbrellas, etc.
Well that's definitely a factor - the other alternative is to only rent ahead (as best you can schedule) for days when you think you might NEED a cart. If there are some days the cart might sit at your site, why pay for it?

Also no car means you are forced into Disney transport and can't drive to/from parks like EP, DHS, AK or Disney Springs.
The carts are "fun" for sure. And we've rented carts maybe 3-4 times in all our stays when we had some more elderly family members there who could not walk the distances all at one time that we can. And once we only got a cart for only a few days of our entire stay.
So without a car and forced into Disney transport in all options otherwise,
@Kite16510, the cart helps you on the Fort legs of travel at a price. But everyone's case is different but this solutions fits yours as you say.
Bama Ed
PS - in our situation, since we drive to WDW, we stay at the Fort and walk/bus to the Fort dock for MK days but drive to the other parks (EP, DHS, AK, DS) so no cart needed.