In the motions of distant solar system objects, astronomers find hints of Planet Nine

[Warren DeMontague]

13. Well, that's the whole point. If Pluto is categorized as a "planet", we have thousands of planets

Which is why categorizing such objects as dwarf planets or Kuiper Belt Objects makes more sense, because none of them fall into the same broad category as the 8 major planets.

The definition worked out by NDGT and the IAU in the 2006 works just fine:

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

IAU definition of planet
From Wikipedia, the free encyclopedia
This article is about the formal definition established in 2006. For prior usage, see Definition of planet.
Euler diagram showing the types of bodies in the Solar System.

The definition of planet set in Prague, Czech Republic in August 2006 by the International Astronomical Union (IAU) states that, in the Solar System, a planet is a celestial body which:

is in orbit around the Sun,
has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
has "cleared the neighborhood" around its orbit.

A non-satellite body fulfilling only the first two of these criteria is classified as a "dwarf planet". According to the IAU, "planets and dwarf planets are two distinct classes of objects". A non-satellite body fulfilling only the first criterion is termed a "small Solar System body" (SSSB). Initial drafts planned to include dwarf planets as a subcategory of planets, but because this could have led to the addition of several dozens of planets into the Solar System, this draft was eventually dropped. The definition was a controversial one, and has drawn both support and criticism from different astronomers, but has remained in use.

According to this definition, there are eight known planets in the Solar System. The definition distinguishes planets from smaller bodies and is not useful outside the Solar System, where smaller bodies cannot be found yet.

it's only a "dick measuring contest" for people who have thrown unreasonable emotional or sentimental attachments onto this topic.


Also, you are incorrect. We KNOW Eris is at least as massive an object as Pluto. This is not some speculation. Like Pluto, Eris also has at least one moon.

https://en.wikipedia.org/wiki/Eris_(dwarf_planet)