I'm on 2021.2.1f1 as well and the issue is TERRIBLE. I'm getting 30 second reloads even on brand new, empty projects, out of the box. It also takes 5-10 minutes to simply open a project, even a new one. While I am using a somewhat older machine, I was dealing with very brief (2-5s) reloads around 2019 or so. I have even reinstalled my operating system (Win 10) fresh within the past year and the issue with Unity persists.