Gay is better than Simmons and Dedmon combined, and since he will be taking those minutes, that's the better comparison. Forbes now is better than Forbes before, which is all that matter for a guy who figures to only get very situation minutes. However, yeah, he's at least as good as Simmons was. Jon wasn't good last year -- he just had a volume-shooting series against GS to get hype.
Most of the things you're trying to laugh about are focused on the 9th-13th men on the roster. Of course those guys aren't as good as the rotation players of last year -- they aren't competing with those guys. Again, trying to criticize the team's performance this year given how much they are playing their deep bench is really dumb. Pretty much no other team (besides Golden State and maybe Boston and Houston for spurts) is going to win games missing their top guy and multiple other rotation players. If you told anyone before this year began that the team would be where they are now with Kawhi missing half the season, not even optimists like BSF would have believed it. That's why it's utter bull to see the same krew try to clam victory now.
They want to say "

This team without Kawhi won't get out of the second round

" when they were saying "

This is a lottery team without Kawhi

" It takes a certain kind of cluelessness to feel vindicated for ting on the non-Kawhi roster.