There's been a lot of interesting responses either way, and I dig seeing everyone's thoughts, even those against the idea! It definitely brings up some interesting issues.

What if you just treated it sort of like creating your own macro, where you just gave players to build their own "combo-buttons", selecting up to X number of actionns to condense into a single button?

It would not only be completely optional, but it would also absolve the Devs of needing to "just create combos".

I think it's pretty clear that that even within "combos", for some jobs there is a bit more nuance where you might not ALWAYS want to follow the same combo string. So you'd be free to just not use a combo button at all, or even just deviate from the button when you wanted.

To me, it seems like a pretty happy medium.