@Suiseiseki remember back in the days of the WRT54g when every router had firmware that just werked? those days are over.

https://openwrt.org/toh/netgear/r8000
https://forum.openwrt.org/t/is-the-netgear-nighthawk-r8000-actually-an-exception-to-broadcom-chips/200247

It's even better with some other chipsets. You gotta buy the Very Specific Router Chipset to get working Wi-Fi. This was a router at my old house that was a real piece of crap that overheated.
https://forum.openwrt.org/t/openwrt-support-for-tp-link-archer-ax50-v1/105076
https://www.reddit.com/r/openwrt/comments/i15dyo/tplink_ax50_how_soon_openwrt/

Also there's AX routers with OpenWRT, but like I said you gotta buy the Very Specific Router that your local Wal-Mart or even Micro Center probably won't sell:
https://openwrt.org/toh/views/toh_available_16128_ax-wifi

As for Tivoization, lol lmao, one vendor tried to lock it down and it was a mess. But it has happened at least once.
https://ml.ninux.org/pipermail/battlemesh/2016-February/004379.html
https://lwn.net/Articles/695994/