<If circumstances change due to events out of your control, then there are solutions for that.> There literally are no good solutions to that. I went through the whole rigmarole of getting a schengen visa for a specific week and then had to postpone my trip by a week due to change in business plans. The 'solution' was to get a second schengen visa for that second week, by submitting the same documents again and paying the same fee again. Which involves showing up at a consulate in-person. Which are not in every city. (source: https://manila.diplo.de/ph-en/service/visa/faq-gq-change-vis...)

Literally nothing would be different if they decided to grant you the visa for the duration you asked for but allowed you the flexibility to make that trip within a time window. You would still ensure I'm in EU for a limited time, but allowed some flexibility.

Secondly, none of the measures like asking me to show booked hotels or booked flights actually ensures I wont be overstaying. I could very well show you all of those and overstay if i wanted to do so illegally. All it does is forces people to shell out of a bunch of money even before they can be sure I'll be granted the visa.