It is time to get rid of them SE...

[Taranok]

Exodus, you have to break a few eggs to make an omelette. It's clear the current design of Summoner is broken, and it's clear the devs have repeatedly stated that they hate pets like the egis from 2.0. Where there's a will, there's a way, and we can very clearly get a much better class if the devs are willing to rework the class, which they should have done alongside MCH instead of doing a minor rework that functionally broke the class.

This is also why I try to find ways to keep the old pets around, at least at lower levels, instead of just flat out ripping them out. E.G. giving Arcanist the trance system at level 4 instead of giving it at 58, and making it summon emerald carbuncle.

If there has to be minor rewriting/retconning of the story because the devs didn't have the foresight to design the class thematically perfectly from the first, then this is one of the cases where I think most players can actually accept it because until SB, Summoner has not once actually been a summoner, and ShB is the closest to SMN it's ever been, but the pet is starting to be a very terrible system that is showing how much neglect it's been given.

[Exodus-E]

Snip.

I won't deny that as of 5.0, SMN has mechanical/play-style issues (as well as potency ones).
But as I've stated multiple times, Egis themselves (aesthetic and concept-wise) aren't a part of its problems.
Else, how come SCH is similar in that it uses a pet to supplement healings, yet it works (relatively) fine for it?

With that out of the way, let's go through some of your points/claims there:

and it's clear the devs have repeatedly stated that they hate pets like the egis from 2.0.

Any sources for that particular claim?
Especially considering all those (recent) Q&As/interviews/etc. stating that they would finally implement proper Egi glamours for SMN in the near future.

If there has to be minor rewriting/retconning of the story

"Minor rewriting/retconning of the story", says you.
An entire entry from the encyclopaedia, artworks, 3D models and story/job questlines + side quests, says I.

As I said before, entirely unrealistic at this point (not to mention divisive for people who actually do like them).

Egis are a permanent fixture of this game's lore/setting, regardless of whether you like them or not.
Anything else regarding SMN is fair game, so long as it works with them (especially with the existence of Trances -> Demi-Primals).