I can personally speak from the 80s, so that’s not exactly a golden age of reliable information. There was concern about scale of infinite growth and power requirements in a perpetual 24/7 full-load timeshare by people that were almost certainly not qualified to talk about the subject.
I was never concerned enough to look into it, but I sure remember the FUD: “They are going to grow to the size of countries!” - “They are going to drink our oceans dry!” … Like I said, unqualified people.
Another factor is that there aren’t that many supercomputers in the world, a handful of thousand of them.
They never took off like the concerned feared. We don’t even concern ourselves with their existence.