That's not a knife edge, counterculture is by definition not mainstream, and certainly today most people are not active participants in counterculture, but it has become easier to participate in countercultures if you so choose then ever before, and (while still being a very small minority) the absolute number of people participating has never been larger. The distinction between impact and mainstream impact is a very important nuance.

There are certainly creators today who are as influential to their groups as the Velvet Underground was to theirs, but just like plenty of people had never heard of them in the 60s, you're probably not going to know about them for another 20 years.