back in the early days, many two strokes had iron bores, and it was really uncommon to get more than maybe 100 hrs of use. Iron rings in an iron bore, using iffy oil. Filled rings helped a little, but not much. Eventually the rings got glued into the grooves, blow-by cleaned a lot of the oil off the cylinder walls and things went south in a hurry.
Then came along chrome bores. Some lasted well, some were flaky. Really...as in chrome flaking away. And we still had problems from iffy oil and carbon build-up.
Nickasyl and clean-running synthetics have changed all that. BUt all the same, I'd suggest that its rare for saws to exceed 2000 hrs...besides the humorous post I made earlier! A 50cc saw should have no trouble delivering 3 hp...thats roughly 100bhp/liter. But it IS delivering near its peak capacity most of the time. That's a little like expecting a high-performance car to last 2000 hrs times 60mph (120k) while pulling a trailer heavy enough to require the pedal on the floor most of the time.