Chunk loading/generation is significantly slower than in 1.17.1

Chunk loading/generation is significantly slower than in 1.17.1. This also affects the time it takes to create a world. Of course this is expected to a certain extent, as the game has to calculate more biomes and more blocks.

Generating a world with seed 10 took about 21 seconds in 1.17.1 and nearly 54 seconds in 21w37a.