Air density on Venus is 90x that of Earth.
It could very well work there and be impossible to build here.
Here on earth, water is roughly 780x the density of air. If you can’t first build a self contained floating city on water, then attempting to do so a few million miles away might be a tad bit more problematic.
Air density at the surface is 90x earth, they plan to float these at 50-70k above Venus where the air density is half that of sea level on Earth.
The interesting thing is at this altitude not only is the pressure human comparable but the temperature is as well 20-30C that’s fall in Texas temps. No pressure space suit needed you could be in a hazmat suit with an SCBA tank and go outside the blimp. Which at this density altitude normal air of 78%N2 22% O2 would be lifting gas you could literally live inside the blimp’s flotation envelope which is probably the plan all along. Have that massive air volume that is holding the blimp up double as habitat space with walkways and platforms most of the internal volume would still be lifting gas.
The real trick is how to inflate the thing before it sinks so deep that the temps melt the envelope. My plan would be reenter using a inflatable ballute heat shield that would automatically double as the initial pilot lift envelope then when subsonic inflate the blimp proper. Ask the Russians they have already sent balloons successfully to Venus on their Vega probes.