Similar for me. I have an old Philips “smart” TV (actually today it is very dumb as basically all services are disabled and all apps heavily outdated) which I occasionally use for watching TV, but most times I use the attached Raspberry Pi with Kodi for watching German public broadcaster’s Mediathek, Youtube or Amazon Prime.
In Germany, you may also use the built in DVB-C receiver of the TV for free TV and an additional CI module + card for pay TV. But cable companies want you to use their set top boxes.
But, yes, if you use a set top box an extra speakers with your TV, the TV basically becomes a large monitor with a remote (which isn’t necessary as the set top box usually comes with a remote).