"Break free from Google" and buy a Pixel phone from them to do so.
But unironically Pixels are currently some of the best actually open phones. They do not lock down or require shady practices for unlocking the bootloader (although they do require a network check once that happens automatically, but it will permanently allow unlocking the bootloader if successful once. Pixels are very easy to restore and almost un-brickable, allow bypassing the boot screen warning by pressing the power button twice, actually allow relocking the bootloader and don't void your warranty unlocking it, don't have a shady one-time fuse like Samsung phones do with Knox, etc.
I have a Pixel 6a with GrapheneOS. Runs great for years, except for one or two apps that require an "official" Android.
Anyway, I now need to get the battery replaced, because apparently they are dangerous and Google pays for the replacement. Unfortunately, the replacement process requires the stock android to be installed. Meaning, I would need to backup the whole phone, reinstall stock android, then restore everything - and hope the whole ordeal works out.
I've wanted to try this on my old Pixel 5, but it has the dreaded screen/motherboard failure. It appears there is no solution for that short of replacing the screen/mobo, which i've already done once after cracking it.
Pixels are really great despite being from Google. I hope they will continue to make them unlockable/relockable. As you say they are also surprisingly hard to brick. Here is someone trying to break it intentionally during the GrapheneOS install:
https://www.youtube.com/watch?v=ik0AiO0WtuU
If you don't like giving money to Google, plenty of companies offer refurbished Pixel phones.