The treads on the plug are worn down? No, not common for a drain plug. I’ve got one rig I’ve changed the oil on 45 times, the drain plug is fine. I’d like to think the threads on the pan are healthy and there’s no drips involved.
So you mean the “dip stick” or the rubber plug about halfway up the side of the block where oil can be poured into (I think this is what you mean). And you don’t mean the threaded cap on the top of the engine that has the word “oil” embossed into it. For further reference the plug on the bottom of the engine’s oil pan from which oil is drained is called the drain plug (there might even be two of them if the drain plan is split by the front drive shaft).
Whatever it is that’s worn out, replace it and it should be fine.