I think it's because they extract compressed rootfs tar each time to be mounted in LXC container. Even with a beefy computer, it takes considerable time.
No, just roll on with it.
There was a period of time, around 2010-2015 when I really felt that computers were fast. SSDs were getting more affordable and that was a huge improvement, every action was immediately responsive. In 2020, that has somehow been undone. It takes 5 seconds to launch a calculator. Software guys really like to undo all the advances that the hardware guys are doing.