As the tech shrank to smaller and smaller electronic parts the speed could increase, as long as the heat could be dissipated. But at a certain point it is difficult to get the heat away, And the materials used, start be be affected by quantum affects; they being so small these effects are no longer too small to ruin anything. This means a new technologies are needed to improve on what we achieved so far.
Of late the solution has to been to stick with what we can manufacture already but process things in parallel to gain speed. But one can only go so far in being able to split tasks to different processors and then combine the results before the solution starts to become as slow as the original designs were.
TV standards are more a case of a need for a dominant technology to become cheap enough to sell, and the ability to stream the data commonplace. Mainly commercial issues I believe.
Battery tech is galloping on apace but again one needs to discover the combination of sufficiently common materials to achieve faster charging, and large capacity. It's asking a lot. Oil holds massive amounts of energy in a small mass, it's difficult to replicate that.
Advances come and go in spurts. I'm, unaware of the rate of new things slowing down. Merely slow downs in areas that were phenomenally quick in improvements over the last few decades.