I enjoy Matt Levine's facsincation with the business of ransomware. He wrote a post early last year [0] on LockBit's business model and how the optimal amount of crime for them to commit is close to, but not quite 100%. It appears they may have tipped too far in the "too much crime" direction.

Another good look at LockBit is an investigative report [1] that goes in depth on how they've survived for so long.

[0] http://catless.ncl.ac.uk/risks/go/33/60/7

[1] https://redsense.com/publications/lockbit-story-a-three-year...