Are there router/(cable)modem combos that can use OpenWrt where the modem actually works?

I need a new modem/router. The one I rent from the ISP sucks and does not have any native VPN support and just generally speaking isn't very configurable. I just recently learned there are projects such as OpenWrt and Merlin, etc., but so far 100% of the examples I've found that were router/modem combos the modem function doesn't work.

Are there any that do work? If no, then is there like a fork of OpenWrt that has something that might? Really trying to find the best/nicest hardware I can possibly get.

Thank you

There is no open source firmware for cable modems or combination modem/router boxes. A two-box solution is common: a simple cable modem that is only a modem combined with a separate OpenWrt router.

Okay. What is the "best" router that supports open source firmware in your opinion? You can flash open source firmware to a Netgear Nighthawk right?

Guess I need to do some research on cable modems now. I don't actually know much about them. Not as much as routers anyway. Have any source recommendations?

On select models.
Refer to the OpenWrt Supported devices