Some context for those angry/confused about RR's appearance at Colbert's last show
Here's some background as to why RR might have been at Colbert's final show. This is conjecture based on what I know of recent late-night history, but my best guess is Colbert and the other late night shows have a contract w/ Mint Mobile from way back when, and RR is now exploiting that to get himself "good" press.
So during the 2023 WGA writer's strike, the 5 late night hosts got together and did a podcast called Strike Force Five to raise money so they could continue paying their entire staff & support the writers during the strike. This strike ran nearly 5 months, and was the second longest in WGA history, leaving millions of people out of work, including hundreds on just the late night shows (Colbert alone had 200 people on staff, so Kimmel and Fallon probably roughly the same, while Meyers and Oliver might have a little less. So anywhere from 600-1,000 people on the 5 late-night shows were going w/o pay. I know the hosts themselves covered some weeks of pay for their cast & crew, but even they don't have the sort of money to cover 5 months of pay for hundreds of people)
Enter: Ryan Reynolds.
At this time, no one knew RR was evil (the late night hosts should've had some idea, but even according to Kjersti Flaa, RR had a great rep and even she liked him before all this. I'm guessing RR's psychotic nature was strictly kept within studio & WME, and extremely well-controlled around people in press, aka late-night hosts), and RR stepped up, and seemingly out of the "goodness" of his heart, bankrolled them through Mint Mobile, allowing all the late night hosts to pay their staff. He made appearances on their podcast which got them more streams and press, and overall did them a solid.
Knowing what we know of RR today, we know he did this so that he'd have power over the hosts "owing" him, but at the time, no one knew what a POS RR was. But now, because the hosts took money from him and signed whatever contracts they signed, RR is using them to get himself in front of the camera and to show that he still has power.
It's Machiavellian and disgusting, esp because for the late night hosts, they did what they did to support their crew who can't afford to go months w/o pay, while RR did this to have ammo in his back pocket.