The USSR was a dictatorship

No it wasn’t. This is propaganda. Even the CIA admits that it is propaganda in this document:

https://www.cia.gov/readingroom/docs/CIA-RDP80-00810A006000360009-0.pdf

Democracy under socialism is simply structured differently. You need to study it properly.

Several countries that you support today still use a system very much like this. Cuba and Vietnam for example. A solid video on Cuban democracy is here: https://youtu.be/2aMsi-A56ds

All the socialist countries built on this system.