I grew up racing dirt bikes, first "piston port" Bultaco's thru the case reed / exhaust valved Honda's. Then into the four strokes. So much development and subsequent innovative designs came out of that horse power race, especially in the 125 class. KTM had a hot rod around year 2000. I think physics and cost brought the development to a point of diminishing returns. Some may remember the differences between the on paper 2000 Honda 125 and the competition where the reed block and housing simply got too big...too much volume. Fast but peaky , they had found the boundary went a little past. ( of course the same company tried oval piston v8's to get valve area to compete with two strokes earlier in their history ) Also have been a out board mechanic/enthusiast since 1978 on and off. Also watched a similar evolution. Outboards designs relied on reeds before the single cylinder dirt bikes for obvious reasons. The old 1950 era mercury's had that goofy reed block surrounding the crank. That design persisted into the "classic" 50 four cylinders.....decades. All the OMC/Johnson/Evinrude depended on reeds. And when the "loopers" were releaseed, it was like an outboard revolution! Some really cool designs happened in the 70's into the 80's. One of my favorites were the v6 mercs. They went thru displacement increases and reed block changes to get to the HP the market was looking for. And the saws....they also relied on reeds in the early days. I think the Husqvarna L65/L77 were among the first truly modern piston port designs. Always loved how the service requirements drove the designs.....saws being light and cheap to manufacture pushed from reeds to piston port designs and were getting "enough" power along with the light weight and smaller over all package sizes while out boards went all out with big carbs/fuel injection with reeds to fix the resultant issues. Motorcycles ..... went all out with expansion chambers, exhaust valves, water cooling, BIG intake ( for displacement ) and reeds as the out boards.....then epa to 4 stroke
. Also Evinude "E-techs" might be the last two strokes as now OMC is gone and four strokes rule for out boards. But the point relevant to the thread is those reed valves allow so much and in my most humble opinion allowed the two stroke to stay in the market longer vs. the typical piston port designs. Who knows how that concept could be applied in different parts to drive to a different set of design objectives.. I have a hunch we won't see as the battery is going to eclipse our favorite way to produce power.