For some reason on 1.18.2 there is a noticeable delay in joining worlds, the "loading terrain" screen causes this delay but this was not an issue on 1.18.1 or previous versions. You would never see this "loading terrain" on previous minecraft versions, this has appeared in 1.18.2 though. This is especially noticeable on multiplayer servers when you teleport from one world to another. I have no idea what 1.8.2 did to cause this regression but I've made a comparison video of joining a world on 1.18.1 and 1.18.2 where you can see the delay. Again, this delay is a lot more noticeable when playing on multiplayer servers and teleporting across different worlds but in my comparison video I'm using singleplayer.