Most of the titan subclasses are fine, the reason you see more warlocks and titans is due to the low build potential with titans. Bungie has hardcore designed titans to be all close and personal and well we are in a shotgun/fusion rifle meta so these titan builds are just so bad to use. Titan supers also happen to be the most lethal in the game so majority of them are tier 1-2 and thus rarely ever gets 2 supers per match. That alone turns players off from wanting to play the class. Warlocks and hunters have more one and done supers so they can be used more, thats why the only titans you will ever see is the mid tree arc titan. The super cooldown changes are just bad in general but whatever we gotta live with it. Anyway titans are good, really good but also really bad due to the reasons I previously described.
New Titan builds for pve but pvp I don’t see much for builds on yt for them outside of 2 or 3 bottom tree hammers build. After the nerfs to bottom tree striker people started jumping ship.