It's a 2017 article, but according to this, the two personal computers with the lowest input latency of all time are the Apple //e (1983) and the TI-99/4a (1979)
And the highest latency was a Symbolics Lisp machine from 1986. It's not the transistor count, it's the depth of the abstraction stack.
In particular it's the depth of the abstraction stack divided by transistor count. Wirth's Law: "Software is getting slower more rapidly than hardware is becoming faster."