i'm sure we could find a form of granularity that doesn't take multiple hours, overly simplistic combat doesn't appeal to me.
Simplicity and granularity is a scale, but I think 5e is slightly, not very, too far to one side.
If you have every character trying to optimize a main action, bonus action, move in one or multiple parts, and an object interaction doing something, it does not seem so bad. Then multiply that by every player at the table, plus dithering over what spell or bonus action to pick, and it becomes a problem.
The trick about reducing, even slightly, 5e's action economy is any benefit is felt five-fold. The benefit is not in you doing less. It is in everyone else going faster, so you get back to your turn faster. Faster combat rounds also means more reactive feeling combat.
Part of this is of course, that 5e monsters are bags of hit points and so hard to be reactive to. Shortening turns only also works if monster stats around hp are also lowered. There's a reason half a dozen combats per four hour session is more normal in OSR type games. 5e will never approach that as long as five different things to do every turn with decision points for each exist in the base combat framework.
All I'm saying is that I have heard plenty of complaints about 5e combat not being satisfying. I don't hear people complaining that the combat is too fast
