I’ve been doing some fairly intense analysis of the changes '24 brings and I think I’m ready to weigh in with an opinion:
The new books change a lot of small things, usually in small ways, and add some new features that are, frankly, not much to consider. In-game crafting isn’t nearly as exciting as questing after information and dungeon-delving to retrieve some ancient artifact of power. Building and maintaining a bastion - a fixed location fortified against level-appropriate threats - is only exciting if you’ve never played SimCity.
D&D 2024 is pretty clearly a revision of the 2014 5e launch and nowhere close to warranting any concern over it being a new edition.
We have the same classes, abilities, and skills; armor class, proficiency, spellcasting, and dice-checks all work exactly the same way; some numbers and features got moved around on classes, some spells were revised in largely unobtrusive ways, and some aspects of character creation got re-organized.
There’s nothing to indicate any of the sort of power inflation that’s typical in trading card games or that we saw with source expansions (looking at you, Tasha’s Cauldron of Everything).
2024 is more structurally formal than 2014, and tries really hard to employ its terms of art in place of lengthy mechanical descriptions. That encapsulation and abstraction will be familiar to anyone who’s done much coding, so it thankfully stops well short of tipping over into the realm of tax form instructions.
I’ve seen criticisms that WotC is working to make the game system easier to express in application code - there may be some truth in that, but it doesn’t seem to have come at any great cost for the analog players (so far, at least!).
The updated language is crisp and precise in ways that may alienate fans of the old High Gygaxian tomes of narrative explanations of systems. I’m not unsympathetic, but I do prefer the new style because it’s closer to how I conceptualize.
Overall, it’s not a tectonic upheaval that overturns all the knowledge and mastery we have in this game - and that’s great! It is a slight tweak on so many different parts of the game that it makes us (especially GMs) have to go back and look up just about everything to do with the game - and that’s… Not Good. My own, aggregate conclusion is that it’s still every bit Fifth Edition Dungeons & Dragons, cosmetically-enhanced warts and all; people who embrace the changes will adjust to them and quickly stop needing to run back to the core books; people who reject the changes will carry on playing their 2014 games and have to deal with the frustration of online tools (like Beyond) constantly showing them things they haven’t yet adopted into their games; people who try to straddle the 2024 line and cherry-pick the things they like from each revision will more than likely find most of their preferred options in 2024.