After all, the internet came directly from the Department of Defense funded ARPANET. Before that, computers were so expensive and large that realistically only governments or large companies could fund even routine work with them.
I suppose all that's changed is now the average human is on the internet. I mean that literally, since it seems that we are about to cross the threshold of 50% of humanity using the internet (https://en.wikipedia.org/wiki/Global_Internet_usage).
So the things governments wish to do on the internet are more and in line with things that involve the population at large. For better or worse (mostly the latter, IMO) that involves lots of intelligence gathering, copyright enforcement, and national security work.