It's been half a year now at least that this change was introduced and it's super annoying. I discover this behavior on MacOS many years but now this is happening in Linux. Because of that I really want to change browser.

Am I missing a reason for such a change?

Edit: to be clear I always setup Firefox to ask everytime what to do but the open option used to open the file without downloading it (or probably in a tmp folder somewhere) now with the open option you have the file in your download which misses the point of asking in the first place.