Both can be true:

1) The original BTC paper was a huge breakthrough in decentralized systems.

2) Most "blockchain" projects today are merely elaborate Ponzis.

Byzantine fault tolerance is definitely a real problem.

For whom? Folks at Google, Facebook, and Amazon that are building distributed databases aren't re-writing their backends to use blockchains, for obvious reasons.

As for people who aren't building general-purpose distributed databases, a solution to the Byzantine generals problem is more of a solution to a problem that they don't have - as other posts in this thread demonstrate.