I would NEVER recommend a modern HP printer, but...I have a HP Laserjet 4000 (Circa 1997) that I 'acquired' from the company I worked for that went bankrupt.

This thing refuses to die. current impression count is over 500,000 prints. All its patents expired over a decade ago, and it's still easy to find parts and toner (originals, and now even 3rd party knockoffs). It's old enough now that modern generic drivers have built in support for it. The only parts I've ever had to replace are the rubber sheet feeder rollers which dry out and stop working correctly after 12-15 years.

So, I guess the point here is that some really solid printers were made a couple decades ago, back when manufacturers still took pride in their products, and they are old enough that the hardware is no longer protected by patents (so practically open) and robust driver support without all the bullshit. Picking up something from this era and cleaning it up would come close to satisfying a lot of your requirements.