Concordski: What ever happened to Soviets' spectacular rival to Concorde? (2017)
edition.cnn.com
edition.cnn.com
The second fact which is rarely mentioned in TU-144 write-ups is that the primary reason for its withdrawal was there simply wasn't (and never could be) a market for the seats. Russia and its communist allies didn't have the per capita income to pay for tickets on the necessarily-expensive Concordski. While Western countries didn't have a large market for the tickets (priced the same as regular first class seats), at least there was some market. In Russia, there weren't enough people (any people?) with the wealth to afford to fly the TU-144.
As a side note, you can see both planes together at the Frankfurt airport where they are on display outside and visible from the tarmac when you take off from your Boeing or Airbus flight. :-)