What happens if you neglect front suspension maintanance? My bike has front suspension, which I have never done any maintenance to, and I don't plan to do so in the future either. I've owned it for 10 years now, and it's kinda stiff by now, but other than that, no problems. I don't really need the suspension since I don't off-road - I just want it to hold up and not leak any oil. Will a fork with suspension do that without maintenance?
The fork in question is Suntour NEX 4610 V2.
It will seize which is why you are feeling the stiffness you are right now. It will also probably handle rough roads less effectively.
I would recommend doing the maintenance and that way you could get another trouble free decade out of it or just keep riding it until the wheels fall off of it figuratively speaking.
I am surprised the fork seals have held so long, but at this point I think the fork oil is thicker and probably helping the seals keep the oil in place. I doubt it will leak oil unless a seal breaks from a catastrophic failure, which is hard to predict.