I'm not so sure that motorcycle emissions are much better than a car's, even if they do consume less gas. Cars have very complicated emissions systems and are under stricter regulations.
I've also never been able to get anywhere close to 3l/100km. As soon as you move onto bigger displacement bikes, you're looking at around 6l/100km, which is comparable to a hybrid car that weights 5-6 times what the bike does! It's far from an extremely efficient mode of transportation given the significantly reduced utility.
Regardless, ride as long as you enjoy it, or until you have to recalculate the amount of risk you can afford!
Yea I don’t want to be that guy but my EV that seats 4 uses less fuel to get the same distance when you account for the massive inefficiency of a petrol engine versus that same petrol in a power plant with heat recovery and fancy emissions controls.
It’s fun to ride motorcycles though.