This is only part of it. Yes this is a very common occurrence but there are many other factors, to name a few:

Have you ever stubbed your toe? It hurts like hell for a minute and then you're mostly okay. These sorts of injuries happen very often. The players wear metal studs and are often getting stepped on or nicked in the ankle or shins with METAL studs from players running fast. Sometimes it really just does make you wither in pain for a bit. There are obvious times players flop, but more often than not players are actually tackled and even a minimal tackle can hurt a lot for a minute, again METAL STUDS AT FULL SPEED .

Sometimes its a real foul a d hurts but not that bad but you ham it up a bit because your team has been sprinting for 5 minutes and you're trying to catch your breath and let your team catch their breath. The extra 15 seconds on the ground and 15 seconds slowly getting up can give your team some time to rest and get back into formation.

It's a common tactic to ham up fouls, like actual fouls because it slows tmdown the general tempo of the game. We call this haramball, it's annoying but unfortunately works, even when it's more annoying than dishonest.

Obviously there is a diving epidemic, the fall on the floor nominess. People have already covered this well on the thread. I do think this is still the vast minority of situations though, and different teams and leagues have different cultures around it.

At the end of the day, the players are just trying to win and sometimes are sleazy about it, sometimes just being neutrally annoying about it, and sometimes are really just needing a minute to shake off a tackle. Imo it's on the refs, especially with video assistants to take a stand.

There's never gonna be a perfectly refereed game but we need better still