On 2-stroke engines un like automotive engines,They require service of engine parts more often than a car engine.Most 2-stroke engines are considered a racing engine! For the cr-500 Honda every 6 races or 20 hrs. to tear down inspect and replace piston,rings,or sand piston high spots and fit new rings,and break the glaze on cylinder walls or rough it up either with sand paper or a hone,To seat the new rings.If you run the engine longer you might wear out the cylinder walls and the piston along with rings,Then you will have to o/size or rebore to the next o/size and replace with new pisto and rings

You answer to your statement you are right in all aspects

Question?? Was asked why 2 extra ports in intake side of cyl. after hogging out ports sometimes you loose some of your botom end and mid range. by putting these extra ports in ,It helps to bring back some of the bottom and mid range. and also adding the hole or port to the piston on the intake side this also helps to improve the bottom and mid range after porting,It also helps to lube the wrist pin and bearing.Also it smoothes out the power delivery everywhere.Others ask why we add lube holes to the piston ? This helps piston lube at high R.P.Ms and also helps lube the engine when comming off a long hill with the throttle closed.