The MCC Halo had a graphical remaster on the original engine, that's why you could swap between original and remaster visuals on the fly. The upcoming project is a remake on a new engine with changes to gameplay and design.

The regular multiplayer was great but it's quite similar to Infinite's multiplayer. I didn't like Warzone and yeah the campaign really sucked.

I think the original trilogy (plus Reach and ODST) work because while there's a ton of lore, the really convoluted stuff is kind of at the background to the moment to moment feel of the game. The most forward facing content is a pastiche of other easily digestible scifi that's all mixed together in a fun, interesting way. You've got conventional humans who feel like a straight expansion of the colonial marines from Aliens up against a diverse and interesting array of aliens. The Covenant are a refinement from Pathways Into Darkness and then the Marathon games. You've got the flood as a space zombie change of pace.

It all mixes together well and the more detailed lore can be built on top of it. There are many intentional gaps and hooks which can suggest things without having to be addressed explicitly, leaving room for some mystery.

After those games, the series kind of imploded under the weight of its own lore since the developers/writers chose to bring all of those mysterious elements to the forefront. It gave less interesting enemies to fight, and less motivation to care. I doubt many people have moments from those games burned into their memories the same way moments from the original trilogy are.

343 needs to go back and rewatch the VODs Bungie put out explaining their weapons triangle, and the reason for shields and armor