Yeah it's fairly obscure model, because it was retired much faster than Concorde since such plane is useless in socialism because they are no rich people to pander to like this. It was mostly used as really fast cargo transport plane, but again it's something just regular transport plane were good for with much less resources used.

Western media also don't like to mention it since it's like casual soviet achievment done "in the meantime" vs the incredibly lauded and advertised Concorde. Not to mention Concorde itself faded into obscurity now so there is even less opportunities to mention its soviet counterpart.