The team will not change the Pop system in Stellaris, maybe in a future sequel they make it different, but Stellaris was born with POPs and will die with POPs
Stellaris was born with POPS, but it was not born with Jobs, and the pop count of the old days was vastly lower. Habitats themselves are older than jobs by a considerable margin, although yes they are technically "DLC" content and not "base" content. In fact they've already made at least one change directly aimed at reducing lag on a per-pop basis, namely reducing the ethics per pop from an empire-level complexity to a single ethic.
This is my primary disagreement with you. Planet Tiles was a game mechanic as old as Pops, but they suddenly reworked and straight removed them years after release. Stellaris has completely reworked core game mechanics in the past, sometimes to enormous public outcry, to improve the game. I can totally see the team (or a future one, I've lost count of how many teams have worked on Stellaris over the years) could change the Pop system.
I don't think "pops" as some kind of mechanic will ever go away, but I CAN see them changing it so loads of pops don't slow down the game. Maybe jobs and ethics can be abstracted to the planet level, maybe someone will completely rewrite the code for those things, maybe they will decide to change the end game to slowly turn pops into (in game terms) inert objects that don't need processing as automation replaces all the work that pops perform.
Even if the team is stubborn as a mule, I still don't understand this. If there is a problem, then ask for it to be fixed. And if the people in charge of fixing it won't do so, then go fix it yourself.
NOW that said:
Yeah, that's why i'm asking for an option to disable it. You want the habitat spam? Go for it. Some people don't like it and want to disable it.
No disagreements, totally fine with the option to disable things. I still cannot fathom how "empire size scaled pop growth" is a good idea and have never once changed that setting after testing it.
Sorry, as much as I've dissented on the logic against habitats, I think the more control players have other their game the better. I honestly wish there was a LOT more "galaxy options", honestly. Increasing the maximum traditions, or the minimum, adjusting which ascension paths you can take, turning off planetary ascension "infinite scaling", etc.