This has definitely been true in the past, but devil's advocate, Philly and the Rams have been as aggressive as anyone these past couple years and they've achieved serious levels of success the last two seasons and appear poised to continue doing so moving forwards (at least while their QBs are on rookie contracts).
And not all free agency spending is equal. These contracts that Buffalo for example is signing aren't like the fully-guaranteed deal Kirk Cousins got last year. Buffalo is signing these deals with a focus on remaining flexible so that if a signing works out, great, but if it doesn't, they can move on pretty much painlessly.
None of these contracts appear to really have potential of coming back to bite Buffalo in the ass; the only one that really has serious strings attached is Morse's deal, which could go south if he continues to struggle with injuries but is also probably the biggest upside deal of the bunch.
I was notably pretty pessimistic about the moves that we made last offseason; wasn't a fan of Star, Ivory, or Vontae Davis's contracts, and while I loved Josh Allen and liked Edmunds as prospects, I wasn't really a fan of the trade-ups (especially in the case of Edmunds). I think this offseason's moves have all been pretty solid so far. Brown and Beasley make so much sense on this team. It sounds like the O-Lineman from Washington is a really solid pickup. I like the flier we took on Kevin Johnson and Frank Gore. I think fans should be pretty happy with free agency so far.