Ok, so, Pluto is more spherical than Mercury, but the most important criteria is local gravitational dominance.

Which Mercury has, but Pluto does not.

I do not see how this is a difficult concept to grasp.

Yeah, sometimes you can make a hasty definition, and then refine it to a level of consistent clarity, after it is justly critiqued, though that refined definition may be multi tiered and somewhat complex.

Thats... thats how science works, thats like the entire fundamental concept of it, right there, improving the level of detail to which you understand reality, via empiricism, logic, participatory debate.

The primary purpose of the planet defition refinenment is to emphasize the importance of relative local gravitational dominance.

I'm trying to imagine you using this kind of logic with like, biological taxonomy.

You could just look up the actual astronomical or mathematical definitions of a 'cleared orbit' if you wanted to, you know that right?

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

As a consequence it does not then share its orbital region with other bodies of significant size, except for its own satellites, or other bodies governed by its own gravitational influence.

This latter restriction excludes objects whose orbits may cross but that will never collide with each other due to orbital resonance, such as Jupiter and its trojans, Earth and 3753 Cruithne, or Neptune and the plutinos.[3]

As to the extent of orbit clearing required, Jean-Luc Margot emphasises "a planet can never completely clear its orbital zone, because gravitational and radiative forces continually perturb the orbits of asteroids and comets into planet-crossing orbits" and states that the IAU did not intend the impossible standard of impeccable orbit clearing.

Pluto and other plutinos are bodies whose orbits are significantly governed by Neptune.

Go look at all the numerical values provided by various algorithms that measure essentially the extent to which a celestial body is locally gravitationally dominant, the extent to which it has 'cleared its orbit'.

You may notice that everything considered a dwarf planet scores orders of magnitude less, by literally all the metrics, than actual planets.

And they would have gotten away with it, if not for that one guy arguing about it on Lemmy in 2026.

Tbf, if you were going to keep Pluto in the definition you'd have to include 200+ other orbits

What is going to be funny is if/when they discover planet 9, and all the apparent Pluto superfans just utterly lose their shit when they attempt to comprehend that there can be another actual planet, and no, pluto still doesn't count.