I put my Sugino Mighty Competition ring on my old Colnago in the late 80's, and it lasted until about 2 years ago. Quite a few miles.

I have other rings that are showing a lot of wear quickly. And other rings that look almost like new with 10,000+ miles.

One variable seems to be chain wear. If you are proactive with replacing chains early, the whole drive system will like it (cassette, chainrings, etc).

Let a chain stretch too much, and you could be replacing chainrings with 1 or 2 chains.

Also, not all alloys are created the same. 70xx series for the chainrings???