For this the signifficantly shorter flight time to Venus is a big advantage, not to mention that a lander wont survive for long anyway, further reducing issues with probe longevity.
I just saw an episode of the new BBC series Planets talking about this. One thing they mentioned was that it was seriously suggested even in the 40’s that there could be rainforests and a fertile surface underneath the cloud cover on Venus. Could see the mystery in particular being an interesting thing to grow up hearing about.
https://www.goodreads.com/book/show/23302599
"Тайна утренней зари"/"The Mystery of the Dawn"/"Taina Luceafărului".
As for their space program, I do believe they had almost similar investment for Venus and Mars, just Venus was more approachable and the missions were more fruitful(?). They canceled some Mars and Venus programs in time. Some wikipedia page about USSR space program:
I for example really don’t care at all about potential microbial life vs. extending the domain of earth’s life through permanent settlement and terraformation of both Mars and Venus.
For example in H.G. Wells 1898 War of the Worlds, the bad guys are from Mars, Edgar Rice Burroghs John Carter series is about Mars, etc. whereas engineer cosmonaut Konstantin Feoktsitov wrote that when he was 10 (~1936) he came to a sad realization. Since going into space was better than everything else, any effort he put into anything other than going into space was wasted effort, BUT by the time he got the Ph.D he would need to contribute to that program men would already be on Venus, so he would never be the first to anything[1]. I don't know Russian language sci-fi well enough to guess what the source for this (or maybe was it Tsiolkovsky? dunno), but that suggests to me that the Soviet interest in Venus wasn't just because the US had a stranglehold on Mars or anything like that, it was because Venus spoke to them in the same way that Mars did to Americans. Any Russian speakers can confirm?
[1]: He ended up as Sergei Korolev's right hand man, and was tasked by the Chief Designer himself with stripping all the safety devices out of the Vostok capsule so that it could hold three men [Vokshod]. When Feoktistov objected, Korolev told him if he did a good job, he'd get to take it into space, and Feoktistov accepted the challenge.