Earth's atmosphere is lighter than the Venusian one at that altitude. A balloon filled with breathable air would float naturally. You can't do that on Earth.
https://en.m.wikipedia.org/wiki/Mass_driver
Images (and calculations) in the deck: https://docs.google.com/presentation/d/1r6CPFJ1AX1ZULacguTf6...
Who is "we"?
I for example, have decided, that we colonize the moon first and then go on from there. But since I sadly do not operate a big space agency/company, my decision is not so relevant (yet).
But apart from that, yeah sure, lets build floating cities and (at least partly) self sufficient habitats on earth first, before we try it do it so far away we need at least 6 months to get there.
Why do people work so hard to get out of a gravity well, only to sink down into another one? The moon isn't bad, but the asteroids are where all the action will be. All the materials a civilization could want, relatively easy to access and move around.
We have decided on Mars, can we stop forking it. Have we learning nothing from Linux?
But if you have to, could you hurry up and make a floating city on earth to practice?
People would pay a tonne of money for that, and having floating cities (In reality small communal groups, so more a village) would be very very neat.