Having people be 'working' (whether remote or in-office) for a set number of hours versus having people 'working' for a set output of productivity is a totally different conversation than remote vs in-office work. I've previously managed both remote and in-office teams, and I've definitely see all the things you're mentioning, but I also saw plenty of remote workers who saw their job as just "i will sit in front of my computer for X number of hours and as long as I have Slack open, I will call it work". Instead of "Seat Time", it's "Screen Open Time". There is nothing inherent about remote work that makes people more productive. Unfortunately, I often saw the opposite.

And you're right that it makes management's job easier. It is management's job to make sure that their teams are producing work, and the unfortunate reality of a lot of workers is that unless they have the threat of someone walking by and seeing that they aren't being productive, they will end up wasting a lot of time. This doesn't mesh well with remote work. Not everyone is like that, but many are, and that's enough to ruin the remote work experience for everyone.