It's mostly used to access my home server and my work rig. I don't have a big enough home office to allow me to have multiple desks and monitors. So the server and workstation are in the corner and I remote onto them.
It makes it so much easier... everything is on the same switch. So speed isn't an issue.
But I remember the bullshit #teamviewer pulled a few years back. It was nasty, fake 'commercial use detected' bullshit to try and con you into paying hundreds for a license yearly