I've had similar experiences to you with colour printers from Canon, HP, etc. I also once had a StyleWriter II which, as you say, was bulletproof. I replaced it over 10 years ago with a Brother B/W laser printer (HL-1440, I presume long discontinued). This simple beast - just prints single-sided black and white, that's all - has operated absolutely flawlessly all this time. It's still going strong, seems to get 1000s of pages from a toner cartridge, never jams, never gives any trouble, just works. It has sat beside a series of Canon/HP/whatever colour inkjets that have been replaced every couple of years when they inevitably break down.
So you might look at current simple models from Brother and see what they have.