More or less it had. Except for privileged commie bosses everyone poor. "Rich" had cars (!) Having noticeable business was prohibited. Selling own potatoes on flea market, or growing chicken and pigs was fine.

> The US has drastically lower tax rates for capital gains.

In Mass. it's 10% to begin with.

> I’m saying economic growth is slowed through the economic inefficiency resulting from unequal taxation.

Not sure about this. Do you have examples when equal taxation helps?

By modern standards sure, but they were much better off than medieval peasants who most of their recent ancestors where.

As to equality the economy isn’t just the legal economy. A cop accepts a bribe is making more than a clean cop and greasing the wheels of bureaucracy was really common as was a rather extensive black market fed by production being diverted etc.

It’s quite consistent how effectively people learn to leverage what they have to get what they want.

> Do you have examples where equal taxation helps.

You can look at tax rates vs long term GDP growth and see trends but economic growth isn’t clear cut. The best example is cases where tax breaks for the wealthy has been harmful is the UK which is still doing alright but had massive advantages from it’s early industrialization and colonies that it quite effectively squandered.