Ultimately, speed will increase further in Computing in Memory(CIM)
Heat will increase too. Heat generation is a function of switching speed and there's an ultimate limit at which a single die can't dissipate heat fast enough to stay within safe temperature limits because heat generation is volumetric (the third power or cube) but dissipation is areal (the second power or square). This is well known - indeed a colleague wrote a PhD thesis on it in the mid-80s, and I think we're getting near that limit already.
Admittedly, there are a few use cases where blindingly fast hardware is necessary, but if we improved the currently appalling efficiency of code, it would reduce the need for raw hardware speed by quite a lot in most cases.