macOS Big Sur has ‘bricked’ some older MacBooks, users claim

A number of Apple MacBook users with older machines are reporting a major issue with the new macOS Big Sur update, claiming installation has rendered their machines unusable.

Apple released the major macOS Big Sur operating system update last week, with compatibility extending as far back as some 2013 models.

Continue here:
https://www.trustedreviews.com/news/macos-big-sur-has-bricked-some-older-macbooks-users-claim-4109032