Good may not be the best term, more like necessary given their situation. Goff in '19-20 wasn't the same player as '17-18.
Stafford is like 10 other QB's in the NFL, if you put him in the right situation he can succeed and the team can be a high end team (Carr, Dak, Tanny, Mac Attack, Burrow, Wentz, JimmyG, Cousins, Ryan, Jameis give or take) but he's had a history of injury issues and Woods was a very underrated loss, Whitworth their LT is almost 40 years old and got worked yesterday. Staff is solid but is what he is, he's done this 3-4x in his career in new situations and always cameback to the pack.
As far as mortgaging their future, I think people do tend to overrate that. If I were an owner, I wouldn't really care if I sucked for 2-3 years after going for it, infact that's probably what I'd intend to do. The bag gets split up evenly either way in the NFL.