I agree with that... (well, mostly).
Here's a question: Can you increase complexity of combat (past "swing and damage") without increasing the problem of tracking what's going on?
Cheers!
You can to a point.
I'll give a good 4e example, one powers does 10 damage, slide 5. The other does 10 damage, -4 to attacks (save ends).
In the first power, I attack and do damage. I then immediately use my slide effect, and then resolve any situations that reside from that (such as getting thrown into a fire or something).
This either requires some good imagination or a battle board if you want the power to be effective, however, there is no ongoing tracking to worry about. You resolve the power and never think about it again.
The 2nd power requires ongoing thinking. The -4 to attack rolls has to factored in to the attacks (including OAs). The saving throw has to be remembered, and any saving throw bonuses/penalties applied. And if the saving throw fails, the power is tracked over several rounds.
If you use a battle board (which I would guess most 4e players do) then the first power gives you more than just a swing and damage but the amount of tracking required is very small. The 2nd one however requires a much larger investment in tracking.
That to me is a key division in tracking mechanics. Even you have effects that are instantaneous they can provide diversity without largely increasing the brainpower required to implement them into the game. Its the ongoing effects that generally increase tracking.