It’s actually fairly simpler-
For example there’s RPG bukkit server and it works without too much mindboggling. Like there was an item called slime boots.

Player put items in a dispenser (which server can see) and is allowed to craft an item. This item is just leather boots, but have metadata and custom name that indentifies the object. When server notices the object is being worn, the player gets jump boost and no fall damage.

This seems way simpler rather than imported custom models, sounds, functions, properties, physics etc.

Bukkit is server-type mods, mods that would be weapons etc would be client side and would require the user to download specific mods to access the server.

Only bukkit plugins. Otherwise people would need to get mods themselves. Unless Ralph meant mods as in moderation.

I animate on my phone, yet screenshare to my pc and then broadcast from pc to yt so lol.

Actually me and Squido basically went ded for a while since the server is pain and I did a lot already + school. Yet somehow someone still had used barrier blocks (which requires commands to retrieve in the first place) despite commands removing any amount of players inventory so idk how they did that. Basically someone had their house boxed in with invisible blocks.

I don’t-