It can be interesting to compare the early Soviet space station program with that in USA.
Skylab was launched in 1973 - by that time only Salyut-1 had successful launch and visits with cosmonauts. Skylab was very different - it was significantly larger by size and mass, it's still the biggest single module ever launched to space. Skylab was much more successful than Soviet stations DOS-2 (lost during launch), Salyut-2 (Almaz; lost control, depressurized, re-entered atmosphere same year), DOS-3 (Kosmos-557, didn't achieve desired orbit). Skylab itself was damaged at launch, significantly damaging micrometeoroid shield / sun shade, and one of the main solar panels, and another solar panel was jammed and couldn't be fully deployed. The first crew launched to Skylab was mostly focused on repairing the station, leaving it in much better shape. Skylab made record-long missions possible, clearly at the time it was the most advanced station - which was helped by a significant amount of consumables onboard and the large space available. As is normal for significant novel technology, many things were tried for the first time. The program included space shower, numerous spacewalks, Sun and Earth observations, scientific and medical experiments.
I think Skylab was also important in how it was prepared and built. Not only Skylab plans were testing the option of launching the upper stage of the rocket which would be turned into space station on orbit - using fuel tanks as the main habitation spaces, it was called "wet lab" - but also the size of the very first national station allowed to try many ideas which will be referenced later when working on new designs. However, Skylab was launched as "dry lab", because Saturn-V allowed this simpler option.
The plans were to keep Skylab on orbit until the Space Shuttle would be able to re-boost it to a higher orbit. But the Space Shuttle got delayed (and we had solar maximum stronger than expected), and Skylab crashed to Earth on July 11, 1979.
During later Skylab years of unoccupied flight the Soviet Union kept launching smaller space stations. Salyut-3 (Almaz-2) on June 25, 1974, successfully visited by 1 crew. Salyut-4 on December 26, 1974, visited by 2 crews. Salyut-5 on June 22, 1976, visited by 2 crews. Launching many stations allowed to rely on expertise grown with previous flights while building the next station. However the stations were limited by the available launch capabilities.