This is the 3rd consecutive cour from the same production team because of summer pockets, eps were already getting finished last minute

Many mechanics (projectile trajectories etc) sync across clients online by way of each Switch getting the exact same results from the same calculations. Would take extremely involved analysis and testing to accomplish making two effectively entirely different physics engines behave similarly enough

120fps or delta-time-based physics not being in the game originally is a problem but not even the whole story here.
Switch 1 version won't use them (it can barely handle 60fps without the extra burden of delta time, and wherever Sw2 ver crossplay isn't involved it's fixing what ain't broke)

1440p objectively should be added
I figure the devs would deliberately decide against introducing the design implications of mouse controls to an established existing game, even after determining it wouldn't be hard to implement.
120fps is unquestionably not happening for technical reasons