Well maybe areas that require many transacting parties, like the supply chain.
Or to store critical data in an fault-tolerant way.
Both can be implemented relatively easy and convenient using a classical database.
If you don't want it to be decentralized, a blockchain is not needed for the supply chain. Just host a standard DB and give all actors access to it.
Fault-tolerant storage can also be implemented using a classical database. Just use signatures/checksums/etc.
There are many possibilities.
Using a blockchain is not efficient at all. At least in those two use cases.