Will 8 GB of memory be adequate to operate Big Sur, or should I increase to 16GB or 32BG so I don't get the spinning beach ball?

I have a 2019 MacBook Pro with 8gb of ram and even just with a few tabs open on Big Sur, it is crashing all the time. It was perfectly fine with over 50 tabs on Catalina

From: macOS - How to Upgrade - Apple

Before you upgrade, we recommend that you back up your Mac. If your

Mac is running OS X Mavericks 10.9 or later, you can upgrade directly to

macOS Big Sur. You’ll need the following:

• OS X 10.9 or later
• 4GB of memory
• 35.5GB available storage on macOS Sierra or later*
• Some features require an Apple ID; terms apply.
• Some features require a compatible internet service provider; fees may apply.

Big Sur is humming right along on my 2014 MacBook Air with 4GB RAM. I just ordered a new M1 Mac mini with 16GB RAM as the RAM is not user upgradeable after purchase, and operating systems and applications continue to grow in size.

I heard reports of no issues on Macbook Air with 4 GB of RAM.

More RAM is always better if you run large programs or multiple programs.

I have had no issues with 16 GB of RAM and always have at least 13-14 apps at all times—6 or 7 in Full Screen.

Future proof your mac at point of purchase— there is no user upgrade path.