If you play 1 or V on consoles, there is a large and active playerbase on DICE servers. They also have the ability to run player controlled game modes but those only last as long as the player who starts it is playing.
That said, you can easily find good games and no cheaters that need banning.
I have never dabbled in PC BF1 but have played BFV some there but not lately. I am sure there’s an active group of players though. JackFrags does new videos with PC footage captured a day or two before the video appears. He’s had BF4, BF3 and even Bad Company lately too.
DICE has a reputation for pushing tech and that’s what is really exciting to me with this next game. Not only is it just plain time for modern combat again in Battlefield, it is time for it to look, sound and feel fresh again with lots of detail they couldn’t do in Frostbite 3.
All that said, I think it’s inevitable that old games will lose players, but with Battlefield, the old games are still being played regularly. I was in BF4 PC the last two nights having a blast.