I've tried both Supreme Commander and Planetary Annihilation.

I think what mostly bothers me about updated versions of the concept is that there are too many "this type of unit counters that type of unit" pairs. You'll start a campaign level, build yourself a nice mixed bag of versatile units, and then an enemy will show up with a horde of some specific unit X that completely overwhelms you, because you didn't have enough Z artillery which is like the only effective thing against X.

I rarely had that problem in the original TA. Generally, all units are vulnerable to all other units, so you have to use geography and consistent resource-denial strategy to your advantage.