My Macbook (just) qualifies as supported for Big Sur and is running Yosemite 10.10.5 (OK, I'm a little slack with upgrading). I have completed a full backup to external drive.
The doc says:
Upgrading from macOS Catalina 10.15 or Mojave 10.14? Go to Software Update in System Preferences to find macOS Big Sur. Click Upgrade Now and follow the onscreen instructions.
Upgrading from an older version of macOS? If you’re running any release from macOS 10.13 to 10.9, you can upgrade to macOS Big Sur from the App Store. If you’re running Mountain Lion 10.8, you will need to upgrade to El Capitan 10.11 first.
Should I upgrade to Catalina (the last 10.x) first, then Big Sur (11.x) or just go straight to Big Sur?
Is there less risk of screwing up my Macbook going via Catalina, or is the risk the same?