The USSR didn’t have to collapse. Their communist economy had to modernize and they could had pulled a Deng (Chinese economic reforms in the ‘70s)
“they could had pulled a Deng”
Couldn’t have been done.
The corruption was institutionalized to such an extent as to make that impossible. The breakup was as much about ending Soviet Communism forever, as it was about reviving the economy.
Though Gorby tried to prevent it, the people were done with the institutions of the State. It’s one of the reasons that State assets ended up in the hands of singular people.