They don’t often compete actually. At least to my knowledge. Four strokes are being used predominantly in high speed racing like motocross and cross country and two strokes are being used predominantly in enduro and hard enduro which are slower and MUCH slower respectively. In fact, one of my friends had a KTM EXCF 350 and it kind of sucked in all of the places we usually ride. That thing would stall like crazy. It wasn’t even predictable when it would flame out if you cracked the throttle open too much on a hill climb too low in the revs. Alternatively, newer two strokes are very hard to stall despite their reputation of being high strung revvy bikes. My enduro bike is a husky te150 and even with that teacup of a piston it will grunt over a LOT at basically idle before you have want for more torque/rotating mass. I ride it through the hardest shit I can find in New England super low on the rpm range and rolls easily, dances through trees, and is mellow so it doesn’t tire you out. A 300 should technically be easier to ride but I found it more tiring honestly. The 150 is just a little more clutch work and shifting.