I had to argue with the bloke who came to hook up our fibre. (We have fibre straight to the house)
Insisted that without their special router the internet wouldn’t work properly.
What he really meant is that he’d have to muck around with paperwork to take the 20 sek a month/24 months hardware fee off the bill. (He didn’t do it, I did, eventually. )
It was, quite literally, a 15 dollar router, with a maximum Wi-Fi speed slower than the fibre.
Needless to say, my old router worked perfectly. As did the one I eventually upgraded to.
Only thing they can’t do is connect remotely to my network. Which, to be frank, I’m quite happy about.