As an example, here is the Helix editor (neovim looks just as bad) in Terminal.app vs. ghostty (would look just as good in any other modern terminal).
But in practice 24-bit was an easy lift for terminals under active development ages ago, and in turn made it trivial to have everyone across any platform specify exact colors more easily without any end user customization or arguments about "not quite what I wanted" in an 8-bit palette or whatever. Thus a lot of the ecosystem now makes use of it. Being able to replicate anything yourself, or get close enough, in a smaller colorspace is still extra grunt work for no particularly valuable reason, and could actually add up to be fairly significant work if one has a lot of more complex code coloring themes and such.