Not really saying it is intentional by Google, but I'm a Firefox user and noticed this started happening again recently. YouTube for me is super slow, buggy, not registering clicks, locking the UI.
It did happen in the past and was fixed after around 1 month (which was good because it decreased my time spent on YouTube).
Right now YouTube is almost unusable for me on Firefox with uBlock Origin on M1 Max and has been for the last couple of days for whatever reason. Even disabling uBlock Origin doesn't help.
Just followed the instructions on that post to install the extension that spoofs the user-agent and, believe or not, all the issues are gone... YouTube works completely fine now on Firefox if the user-agent is Windows + Chrome.
It did happen in the past and was fixed after around 1 month (which was good because it decreased my time spent on YouTube).
Right now YouTube is almost unusable for me on Firefox with uBlock Origin on M1 Max and has been for the last couple of days for whatever reason. Even disabling uBlock Origin doesn't help.
Something is definitely going on between the two.