Race development is a process of strengthening the weakest link in your system. It used to be they just needed more power, then they needed better suspension, then better tyres, and on and on. If you strengthen one aspect it stresses another that then needs fixing. Sort of a never ending exercise to improve and balance the system.
It seems most of the MotoGP bikes have more power than the tyres can handle because they spin on corner exit, and unless they are very carefully managed they lose their grip before the end of the race. If Tyres with better traction and longer wearing tread compounds are developed you can bet the horse power will be increased even more. And since we are dealing with physical mechanics I think the Mohr's Law concept is not applicable like it is with electronics. Even so, it is truly amazing the stuff that has been developed for this sport over the years. The venerable Norton Manx had about 50 horse power, the current MotoGP bikes somewhere north of 250HP.