Hypersonics are fast but at the end may not have enough explosive payload to deliver when you optimize it to go that fast. Maybe as a kinetic penetrator against certain targets? Or well the non conventional warheads.
Cruise missiles can fly low and have stealth features. Being close to surface makes it difficult for radars to tell it apart from the ground as well I think when you have airborne platforms, but modern radars might be good enough for that not to matter significantly anymore.
I mean KE and ANKA 3 is flying and being tested, so it's better than having waited for TF6000. As to how many is many or few that's relative. Are we gonna operate 20 or 100 of these? And how long will it take to manufacture that many even? 4-5 years after serial production starts? It would be...
Akıncı has P&W, T929 engine problem isn't new and AFAIK KE already has enough engines delivered for now. TF6000 is being tested so it's only a few years of having to do with existing engines.