We're on Next, but have noticed an increase in scene preperation "preparing objects" on heavy forestpack objects with plenty grass, trees, mulch etc. On a typical small test scene you dont notice this, but on all heavy productions scenes you do.
For example we have a current project where it does a frame in 18 minutes, however only 8 minutes is actual rendering time! About 2 minutes is denoising and exporting render elements, so the scene takes almost longer to prepare than the actual render! It seems to get stuck on preparing forest objects.
It may be related to 2021.1, I can't remember this happening on 2019......