My dad just got back online after years of boondocking it - he likes tactical shooters with a rich map making scene - what's out there?

As in title, my father is an American nomad, and he just recently got a spot with good internet signal for a few months.

He hasn't really played in years, and the last game he really enjoyed was Warface and Novalogic's Joint Operations: Combined Arms.

There is a bit of a twist though, his vision certainly isn't what it used to be, so whatever game I suggest needs accessibility options galore.

I found a really good "singleplayer only" experience in Ravenfield and the style lends itself very well to my father's limited vision.

Is there something like Ravenfield but with a well supported online component? Perhaps Battlebit: Remastered is pretty close?

EDIT: I suppose the genre is better described a "mil-sim" than "tactical shooter".

UPDATE: Someone recommended the latest Insurgency game. After realizing my father had over 1K hours in the previous Insurgency game I realized that this was the game to get. Turns out it was a good choice! That's where most of my father's online buddies ended up! Thanks all! Feel free to keep recommending things, but we already seem to have a winner!