Someone needs to curate and maintain the blocklist. Paying for software once is a surefire way to have it stop blocking anything a few years down the line because the company stopped updating their lists when the sales ran out.
If you pay a set fee for something that requires continuous maintainance you’re either overpaying enough to compensate for cash flow interruptions or you’re at risk of the software being discontinued. The latter is especially true if you’re getting stuff for free, but in that case you’re also not entitled to any service.
As for “why not block teamviewer at the router”: because then anydesk will still work. And if you block anydesk, Microsoft Remote Support will work. And if you block Microsoft Remote Support, RustDesk will work. And if you try to block every single RustDesk server, grandpa’s internet probably no longer works anymore, because you’ve just blocked off every data center in the world.
If apps don’t do anything weird, this stuff should work automatically. Most of my issues with password managers stem from apps that decide to throw all standard components and APIs away and redesign the concept of “text input” from the ground up.
I believe banks do this intentionally so malware can’t automatically enter input without additional effort. The same bullshit sometimes also messes with browser password managers, like not accepting the autofill or treating the input field as empty unless you typed something into it.