It's what you cannot see that is bad. The peaks of the finish wear as well as valleys between the peaks fill with wear debris. A renewal of the finish is required for the rings to seat properly.
Two-strokes are hardy beasts by and large however the pictured bike is a Bultaco Astro,a vintage race bike. If you want to win,hell if you want to finish the bike must be all it can be.
A lie has no feet......it can't stand alone.............