Stories will usually take a couple of days for the earnings to come in. After that, I'll still earn from them but it's a lot lower and more random.

People do have reading groups, that is why you will see really terrible articles get a huge amount of engagement because they are trying to inflate earnings. Medium will eventually suspend them for manufactured engagement.

However, I know of a few legit writers who get a ton of reads without all of the comments. Many of them are also from Medium and not external reads, so I don't really understand how that works since most people struggle to get any reads after a day or two.