Yeah, there's estimates going both ways for conditions of ordinary people in the European Medieval period. There's probably more than one truth - it was non-uniform and lasted a millennium. It was also a pretty poor region after the collapse of Rome, so even the rich could only be so rich. Stone age hunter-gatherers would have a pretty much perfect Gini for the same reason.

For richer premodern regions like the India and China estimates are much higher (here's a really recent analysis on some of them). Ditto for societies before the Medieval period, although usually they just go off of house sizes for that and the results can be so high they seem impossible. It's also worth mentioning Gini has some problems for this kind of thing - the paper I link emphasises other metrics more as a result.

Looking at modern dictatorships, Russia is said to have most of the world's billionaires, and their official 2021 value is up at 0.880. Unofficially it's probably worse. Other dictatorships report lower values, but anyone connected to the third world knows they're bullshit and the elites own absolutely everything. The US is also an outlier; Canada is 0.726, Iceland is down at 0.649.

There was only more inequality after the renaissance. Much of that time was democratic.

No? The first modern thing that people will even claim as democracy is the US at the the end of the 18th century, and it was very rich, male and whites-only. Before that you had the age of absolutism, and before that you had various republics like Florence or classical Athens, but imagine voting bodies at least as exclusive as the early US and pretty unstable, with periods of effective dictatorship. Ordinary male citizens gradually got rights over the 19th century, and the first unrestricted, universal suffrage appeared in New Zealand in 1893.

TBF inequality kept increasing in the democratic US, but then it went down in the postwar era, which is unprecedented in history. Being equal before the law doesn't mean equal in practice, but it's just kind of common sense that it would be closer.