The older HP LaserJet 4000 series were nearly indestructible. I supported one that was somewhere in the 700K page rage and only normal wear and tear. Sadly, they do not like water from a fire hose.
I have a Brother HL-2070N B&W laser at home. It’s a little louder compared to similar HP’s but it has only needed regular supplies. Very rarely jams.
The 4000 series HP lasers sometimes seem to run forever.