I've read here a little:
https://hackernoon.com/what-is-blockchain-as-a-service-28667754d6dcImho this could be an option for companies that need
private blockchains for their use, where
decentralization is not necessary.
But a good mention is that it's a buzz. Be aware that after all blockchain is "just" a database and not all projects need this kind of database.
So the answer to the question "woes it worth to use" this.. depends a lot on what you want to use it for.
Then why not a SQL database, which is more efficient, heavily tested, and robust?
OP, "Blockchain as a Service" is not the "current buzz" anymore. But it was in 2016 and 2017 when companies were riding the blockchain bandwagon without understanding what the incentives were in Bitcoin, and why it became the most successful "blockchain".