I wouldn’t fully agree with that. There is some of that, but then also there’s very little historical record of poor people. Up until like 1850ish, only rich people could really read/write, and their books and correspondence is what a lot of historical research is based on. And the rich people themselves didn’t write about the filthy poors a lot. And there are historians that would very much like to study this topic, l but it’s exceedingly difficult for lack of resources.

Now that said, there is quite a bit of bias still. Not just toward poor “unimportant” people, also towards women. E.g. Milan was ruled by the Visconti family, which was a powerful name back then. The last Visconti ruler died, leaving his son in law in power. He’s called “Francesco I Sforza” in most history books, even though Sforza was kind of a minor name back then, and he himself would sign letters with the Visconti last name of his wife, Bianca Maria Visconti. And even his sons (and I think Grandsons) would still use the Visconti name. But because 18th and 19th century historians thought it’s no good to refer to a man by the last name of his wife, and that the wife must have been unimportant anyways, this was the new Sforza reign, not the continued Visconti reign. But we have letters of her managing the whole city while he was off, of her disagreeing with him quite strongly and openly in letters, leading everything when her husband was ill, dealing with diplomacy and military affairs etc. So in a lot of ways they were reigning together, not one single strong man doing everything.

There is a growing group of historians that do study these kinds of things and it is slowly shifting. And I don’t doubt that this also happens in regards to poor people, just less so due to lack of available sources. But of course there’s also institutional pushback, nationalistic infighting, funding being assigned based on biases etc. it’s not all rosy.

And I’m no historian, so this in large part based on the “inventing the Renaissance” book by Ada Palmer(History professor at Uni Chicago and also a really good scifi writer). It’s an amazing read, not just about the period, the different power dynamics and personalities, stuff like homosexuality and atheism in the period etc., but in large part also on how historians work, how perceptions among historians changed through the ages, how some misconceptions (like “women aren’t important”) persisted for centuries. It’s without a doubt the best history book I read in a long time and I can’t recommend it highly enough.