Don't combine it with von Neumann probes and you've solved the Fermi paradox: a civilization that puts that much work into computing power is either doing the equivalent of mining crypto and going nowhere, or is doing AI and is so dependent on it that they inevitably form a vast echo chamber (echo sphere?) that only wants to talk to itself (itselves?) and can't bear to be left out by adding the latency unavoidably added by distance.

tl;dr: civilizations advanced enough to travel between stars end up trapped by the resources and physics required to keep up with the Joneses.