Freesync monitors range from pretty good to trash. While he might be exagering the bad part, his point isn't baseless.
IDK about that. There might be a lot of bad ones, but I'd be surprised if it was most, and I don't believe that they "do not work", that's totally not the same thing as having a narrow range.
I do know that a lot of monitors are trash. If he'd said flat out that "[t]he truth is most of your PC monitors do not work. They do not even work with AMD’s graphics cards”, everyone
ought to respond with ROFL. This is the same thing.
If NVIDIA had published an alphabetical whitelist of an equivalently tiny proportion of all monitors, and users had to use a button to get their NVIDIA GPU to have it talk to the other 99% of monitors that existed already, everyone would take the piss. Same thing.
Like, don't the people with those monitors (and AMD GPUs) already know they're not the best? Why can't NVIDIA just let it work? No-one's who now buys a NVIDIA GPU (when they weren't going to because they didn't want to lose FreeSync) would ever think worse of their new NVIDIA card for it seamlessly working just the same as their old AMD card did with that monitor.