Buran was by all means a better shuttle. Far safer, too. It could fly with more payload than the American Shuttle, and it could go all the way from takeoff to orbit to landing on a runway with no crew onboard, meaning that no crew had to be risked for missions that did not require them. It had far more abort options thanks to Energia's liquid boosters, which could be shut down unlike the SRBs on the American Shuttle. If the orbiter wasnt required, Energia could even fly on its own with massive payload making it more flexible.

Unfortunately Buran was really just the product of the cold war tensions. It was developed as a response to some capabilities the USSR thought the American Shuttle had, mainly in the realm of satellite recovery, which it did not. Therefore, and much like the MiG-25/F-15 situation, it was overbuilt. It came at a time where the USSR was speeding head first into economic collapse and despite the spacecraft's (and rocket's) fantastic capabilities, it just was not possible to finance a program like this. Buran ended up flying once, flawlessly, and Energia twice, equally flawlessly (despite the failure in the actual payload, Polyus).