There are use-cases outside of "crypto" for blockchain - notably for security related use-cases such as historization ; tough I concede that use-case can be handled with more standard technologies it is very fun to get into it and study such use as it may have properties that could be interesting. One has to have some time for this but to be frank it's not really something super hard to pull-off (Bc itself conceptually)
You can make use of merkle-trees when ever you want to proof the data integrity of large amounts of individually independent data (distributed FS etc).
After playing arround with SMTs for a bit, possible use-cases came to mind quite frequently.
The challenge to me is that the ability to prove the data integrity is quite hard once you store the data elsewhere, particularly on a single disk - I don’t know that people are regularly reading and reevalidating the stored data and likely not on every I/o operation.