It's time to ask again: what's MP for?

[Absurdity]

I don't think there would be any particular issue with making MP management relevant if there was a failsafe to prevent mistakes from completely bricking the job unless you carry around super ethers.

Like if there was a GCD button that recovers some MP per use, so there's still consequences for messing up but you also don't become useless for an extended period of time (like MNKs in HW were 2/3 into a long fight without getting Goad).

If only there was a support role that could restore MP (and TP lol) for the entire party...oh wait.

However, I think the bigger question is, what do people actually want to change? SB, every healer/caster had Lucid Dreaming, it is just that the timings about getting the optimal use out of it was tighter.

As someone who played a low piety Astro in Stormblood, the timing wasn't just tighter. I needed to make sure Lucid aligns with buff extensions or actually make use of the dreaded Ewer to stay MP positive.

We can talk about how ranged physicals could be MP batteries, but you cannot guarantee on having an MP battery, so should MP management take it into consideration or not?

You are almost guaranteed to have a phys ranged in the few pieces of content where you are likely to run out of MP.

I also don't think it's the end of the world if bad MP management just results in a failure state.
We had that before and it didn't burn the game to the ground.

is this about making phys ranged a meaningful role that's not caster but easy?

Not exactly, but it would certainly help if the "support" role had more support than "I make you do a bit more damage every 120 seconds".