They did. Vortex, TM, TKM, Biland and others. They never really took off. World Formula was actually a CIK class, not an engine.
Two valve OHV engines work well for karting, small enough, light enough, low enough and make just enough power.
When you try to get to even 80cc two stoke performance, four strokes make less sense. You’re moving to four valves, OHC, much higher RPM and a heavier, taller package. The advantages of having something relatively low cost to buy and maintain go out the window once you step out of the industrial type engines.
Motorcycle manufacturers went 4 stroke because they had no other choice commercially.
Two strokes can be (and are) silenced when needed in karting. Another thing about the faster four strokes is that the lower frequency noise they make travels rather from the track compared to the two strokes.
Good thread on the options over time here: