In short, yes it's very much worth coming back to.
Depending on when you last played, the amount of ilevel reforge options alone just within the last few month is staggering. This isn't including the other end-game venues where really good gear can be obtained (Ark Angels II, Divine Might II, REM Chapter BC's, etc).
If you do come back, take things in stride. It can be overwhelming to see all the new items and changes, especially if you're the type of person that has to have the best stuff for your job(s). It'll take time to upgrade and update your gear.
Find a good linkshell to land into if you don't already have one. While lots of aspects of the game are soloable, there is still content that you'll want to do with friends and other people.