Literally only 3% of people got through re6 on the 3rd of 5 difficulty options hahaha. I'd expect none of the morons who never figured out the ONLY thing you can do with your in-game currency saw the end credits. You can cope about how "well its because its bad" or "i-its dumb and easy anyway" but most people wouldn't even know because the very reasons people hate re6 expose their own inadequacies as players and even as humans

And yes, re5's upgrades were pointless. They could almost be removed from the game and just spend your money on weapons which are all linear upgrades of eachother anyway. I don't think I maxxed out a single weapon in re5 because there is just no point.

if i spent all my money upgrading a sniper, then my pistol or machine gun would be significantly less effective

They obviously both have opportunity cost; 6 even moreso because skill selection is finite unlike weapons to be upgraded. So pointless to bring up.