[Lord Benendearu]

Your reasoning of liking to see people in suits fight is understandable. However, like other posters before me said, CGI does become the norm. The producers would be mad not to use it, since it is cheaper than practical effects, and has the ability to add some versatility.

I agree that Zyuranger's T-rex doesn't look good. I get what they were going for in wanting to make it look more modern, but in this case the GGI is just lazily and cheaply implemented.

Back on topic: I rewatched some of the Go-Buster mecha battles, and the show also has plenty of people in giant robot suits beating each other up.
In fact, there is even an entire episode dedicated to it, where the red ranger and his mech are forced to fight lots of evil mecha...in a boxing ring. And said battles are really CGI-lite.