If you made D&D combat action economy, what would it be?

What would the action economy look like if you were in charge of designing a lighter D&D-like RPG?

I'm asking it as a hypothetical because I'm hoping for some more concrete ideas as opposed to theoretical advice like, "it depends on your design philosophy," etc. That's helpful sometimes, but that's not really what I'm stuck on right now. :P

Optional Reading

In my first version of Simple Saga, you had 2 Full Actions and 2 Half Actions each turn. Full Actions were mostly for attacking, spells, and moving, etc. Half Actions were basically a combination of bonus actions and reactions that could be used for either. I thought it was pretty elegant, but it was hard to teach to brand new players (although experienced players picked it up pretty fast).

Since then, I've adopted a slightly different system. You have 2 Actions each turn for moving, attacking, etc. Then any Free action/Reaction ability can be used once per round. (So basically, no action economy slot for free actions—they're actually free. If you have 3 free action options, you could use all 3 every round.)

I like this version, but I haven't really had a chance to playtest it except by myself. Both versions also don't really do anything to accelerate combat, but I can't think of a compromise solution that still retains some of the mechanical depth. I don't love games with 1 action, and that's it; because you end up moving 1 turn, then attacking the next, moving 1 turn, attacking the next, etc.

You don't have to follow my philosophy for your solution, but maybe stick with something that would fit a generally D&D-ish game. I just want to see what everyone else would come up with.