It’s a tarpit. If they simply displayed a blocked “no vids for u” message, you’d get outraged, go complain online, look for workarounds, and eventually find a bypass. If everything still works but poorly, you get annoyed, turn off your adblocker to troubleshoot, possibly blame the adblocker for being “buggy” and keep it off. Their help page solution implies they are hoping for just that. There is no “smoking gun” blocked message to go complain online about, even though it is indeed their servers that are degrading your connection on purpose in secret. Or maybe you give up and leave their ecosystem entirely, which is no big loss for them.
The proper solution is to develop an adblock that they cannot detect is blocking ads. This may require actually downloading the ad video in background, and then lying that the video has played.
Stripping down to a skeleton of a software is standard troubleshooting procedure. Ever had a plugin crash and consume 100% cpu? I had. Only way to sense is that fans are spinning up and page is laggy, and then look in about:performance and there it is. No one would have ever suspected that the website you’re visiting is deliberately introducing bugs in secret if it thinks you’re adblocking.