I play on an iPad Pro. 

Since Minecraft update 1.18.30 when render dragon was rolled out to all devices ( I think that the correct version) there was a significant decrease in FPS. Flying with elytra was a nightmare if it was not around loaded chunks, anything further means your flying into a blue sky and hope.

Now on 1.19 it’s even worse, I can walk up to a chunk and wait for a minute for it to load.  The lag in unbelievable, it’s even hard to take off with elytra and rocket as it’s so bad. I’m having to climb up high, jump off, activate elytra and then use rocket which doesn’t always work.  I’ve tested this on a new world aswell as existing. 

sometimes the chunks never completely render.