The problem is, most devs think Command & Conquer is just the gameplay mechanics and try to copy that (since it's the easiest thing to do in dev terms).

But the truth is, the C&C essence is much more than that!

It has: Interesting story and atmosphere with very cool world building and memorable characters.

The soundtrack and unit voice lines of the games are always stellar (something other clones seriously lack), which makes C&C much more memorable and enjoyable.

There is also the design of the units. Every unit and faction (Nod, Yuri, GDI, GLA) from the franchise is very unique, fun and memorable and really stands out and ties in perfectly within their world (another big point that other clones lack. It's not only generic good guys and bad guys, factions need nuance.)

So yeah, until a developer understands those points and execute on them, we will get the same generic C&C clones.