It's not as easily obtainable in the US, but the aforementioned Pocophone F1 is usually the phone that's brought up when talking about <$500 phones.
SD845, 6/8GB of memory, 64/128/256GB SKUs with microSD support and a set of cameras that aren't actually bad alongside a 4000mAh battery. It's a shit ton of phone starting from $299 for the 64GB/6GB SKU.
I mean, that was a rhetorical question, but that is pretty much how I think about them.
But just to put it in perspective, even for a premium device they are ridiculously inflated. I can get a 128 GB Note 9, brand new, from the official seller, for $30 than I can pre-order a 64GB iPhone XR. Yes, XR. We are not talking carriers or contract, we are talking the price from 2 "main" official sellers in my country, one time on cash. I am not sure how anyone (not you) can comment that price is not a valid criticism.