I understand your point, but I think it's unfortunately a little simplistic for a number of reasons.
But mainly...we don't know what we don't know. The alternative could be worse; and that is where my family and I are. We are worried about our upcoming trip, yes. But, even IF we re-schedule....there is no guarantee that things will be changed by 2021 or 2022. There may still be restrictions in place. AND the crowds will be much higher by then. (maybe, probably, no one really knows)
If we knew, for a fact that fireworks and character meets and fastpass would be back this date, March 2021 as an example, then it makes it much easier to make that decision to re-schedule.
But right now, a lot of us are in a position where it's the lesser of two evils. Do we keep what we have, knowing that the trip is not going to be the trip we wanted or planned for? Or do we roll the dice, reschedule, and still have a less than ideal trip, and maybe even the conditions are even worse than they would have been?