Uhhh yeah it's a dumb shitty hunk of cast iron. The piston and the fit and finish is slightly better on the OEM Yamaha but not much for like 6x the price. People just have a natural desire to feel like they need to buy the more expensive thing. The Yammy is better but once it's cleaned up, installed, and ripping nobody will ever be able to tell the difference.
They should both get about the same usage. Most cast iron kits last 4-6000 miles if you have them tuned and take care of them. Even OEM service interval is about the same.
I would definitely try to figure out what's going on with the current cylinder since it doesn't sound like you've put a lot of miles on it. You can mess with putting oil in the cylinder or doing a real leak down test but it's usually way faster and easier to just pull it off. The rings could be stuck from carbon (oil injected bikes tend to run too much oil) or maybe it never got a good break in, or wasn't tuned right or soft seized.
If the bore is clean and you can find a stock oem or even knockoff piston that's probably the way to go, but if it needs bored I would just get the niche one and call it a day, maybe sell the old OEM cylinder to one of these guys that think they are magic blessed by the tuning fork fairy.