As an end-user of databases, I hope in 50 years time, there will be no meaningful distinction between OLAP and OLTP DBs.
We spend so much time and energy copying data around into specific data stores to solve specific problems / answer specific questions / enable specific features... It's messy, complex, and adds a ton of overhead.
It could simplify a lot of technology if an operational database could also handle non-trivial analytical workloads.