He had a better QBR than Daniel Jones, Sam Darnold, Jalen Hurts, Drew Lock, Marcus Mariota, and whoever the Saints are planning on starting at QB. Plus has better running upside than at least 4 of those guys. Pretty sure he had a better TD:INT ratio than all of them and had comparable completion percentage.
He was probably better than Zach Wilson, Mac Jones, and that rookie the Texans started last year.
In his prime he could easily hang in the middling tier of current NFL QBs like Tannehill, Carr, Hurts, Wentz, and Tua.
I don’t really care whether he didn’t get a second chance because of his politics or because he wasn’t willing to go through the Trubisky/Mariota path of sitting as a backup for a few years, but saying it’s because he couldn’t perform at that level is incorrect.