Many of us are on DDB because it's a place that lets us access D&D content in a (mostly) streamlined and comfortable way. This new update has un-streamlined it so badly it feels like I'm walking against the wind with an open umbrella behind me.

Forcing 2024 versions down our throats means a large amount of legacy content becomes nigh impossible to play without homebrewing hundreds of subclasses, spells, items, etc.
So many classes no longer recieve their expanded spell list from sourcebooks, and it is beyond annoying to have to homebrew every single one of them.

If the decision is that users here are forced to use 2024 versions when we have had campaigns of many years running on 5e, I think the fair decision for us is to cancel/refund everything, and revert to paper. That way, no one to fault but ourselves.

You don't need to homebrew anything. On home tab ensure Legacy is enabled. When selecting a class the dropdown is sectioned and there is Core Rules, which lists 2024 versions and Legacy which lists the 2014 versions. Choose the 2014 version. Voila, the 2014 class, its rules and all its expanded/domain/etc spells are there and all the usual 2014 spells can be chosen.

Stuff from anything outside the core three books also needs the extended rules toggle.