The empire doesn't get Deleted. If they removed all your settlements buildings wonders, units, etc. and then dumped you into the Advanced start for the next Age that would be Deleting.Build An Empire To Stand The Test Of Time has been the tagline since Civ1. It might even have been that for the board game that inspired it.
Now we have Build An Empire That Will Get Deleted Twice By Developer Fiat And Replaced Off Screen.
Are you seriously going to try and pretend that doen’t conpletely change the core identity and mechanics of the game? Or that isn’t the source of thr majority of the fan backlash that is so plainly evident both in sales, reviews and player count.
Your buildings become obsolete but they are still there
Your Cities become obsolete (towns), but they are still there.
Your Towns and improvements are unchanged (they get a chance for a new specialization)
Your civ bonuses get changed
Your government becomes obsolete (policy slots lost)
etc.
How they frame it (with narrative events and Marketing) is a massive impact (and they could have done it a Lot better)