Why would any company need a slow and inefficient datastructure if they don't need the one advantage of it - decentralization ?
Well maybe areas that require many transacting parties, like the supply chain.
Or to store critical data in an fault-tolerant way.
Consider a private blockchain as a p2p database, which guarantees robustness and fault tolerance.
Sharding and Distributed Database already achieve points you mentioned. Fault-tolerant also could be achieved on hardware level (extra PSU, RAID 5 SSD, etc.).
But it's different case when we're talking about public blockchain where transparency is necessary.