Technology

In Europe that used to be the case, but that changed not that long ago. Now providers are legally obligated to allow you to get your own modem

You need to use their modem quite often, but you don’t need to use their router. They’re usually “all in one” modem/router things these days, but they’re legally required to provide you with a modem in bridge mode if you ask — at that point, an Ethernet cable attached to their modem is effectively attached to the Internet, and you can put your own hardware inside (firewall, Wifi router, etc.).

While you need to connect to their IP gateway, you don’t need to use their DNS services or anything but their IP gateway service.

Yes, look on their website for compatible models, there’s a handful of affordable ones, many which perform better on higher tier connections too. Been using my own modems with Comcast for 25 years.

I wouldn't trust them to not randomly enable WiFi, but you can also use their modem but disable any built in WiFi on it & still use your own router. ISPs continue to try to bundle their modem & router, which gives them complete access to your home network. Some lucky people have found fiber providers that let them use their own SFP.

"cheap" is a relative term.

Nobody should be buying a DOCSIS 3.0 modem these days. They are obsolete and for some reason still being sold.

A decent DOCSIS 3.1 modem is at least $200. A Next Gen like S34 is at least $220. At least at the big blue big box store. And then you have to get your own wifi.

(However, that big blue store also will give you a 15% discount on any networking purchase if you recycle an old network device...I traded in an old modem but you should be able to find a switch or router at a thrift store and still come out ahead)

It pays for itself pretty quick (by not paying rental fees), but that doesn't necessarily make it cheap.

I absolutely prefer using my own equipment, and do...but it's also worth mentioning that in many markets, Xfinity removed data caps if you have a rented modem.