To re-iterate what some of the above posters have said, he is definitely still worth it… If you do not have heroes that does what he does.
With expanded hero rosters as this game grows, there would be times when new heroes will start incorporating what some of the existing heroes do. For players who are not spenders and aren’t lucky enough to pull the other heroes who does what Wu Kong does, namely Tarlak, Ranvir, and Miki (which is me), you take what you can get to still get a competitive edge and contribute.
Let’s not forget that Wu Kong is a classic 4* (others being 5*) and is available to every player once they start TC13, or TC20. Tarlak is now available for a few days each month (unless you spend gems, the more you complete the Atlantis stages to get the guaranteed 1st time completion rewards or the mission rewards for solving the mysteries of Atlantis (both difficulties), the less channels you have to accumulate enough Atlantis coins to use Atlantis coin summons), if you missed out on Ranvir, you’d have to wait until he returns in a future Atlantis portal, and same thing would be for Miki, once August 2019 ends.
Sure his misses are annoying when you see them, but Wu Kong is still a viable hero to potentially get huge Titan damage, Raids, Raids Tournaments, and Wars. And the chance of access to him is much higher than his higher starred counterparts, very important point to keep in mind for F2P/C2P player base.