Got one when I was 6 I think. Got a Master System the following year. Inherited the old toploader at some point as well.
Yes I used to spend hours on it but from memory it was only really in the winter when I had to be inside anyway. The rest of the time I’d be at friends houses or out pretending not to be causing trouble. As long as your kids are otherwise leading healthy and fulfilling lives then you can do a lot worse than give them a telly.
How are you going to police a 5yo watching late-night grot whilst you’re asleep?
Most TVs have parental locks so you can lock out anything rated above a certain threshold. Just make sure you get one with that on and you’re sorted.
TV can also double up as a computer monitor if that’s another consideration (and miles more practical for homework than a tablet).
FWIW I refuse to have one in my bedroom now (for reasons already explained) and haven’t reconnected the satellite since we got the extension built about 7 months ago (but still paying the licence, mug.)