It may be less popular for new projects, but every single project/product/service that's using Oracle DB is gonna continue to use, and hire, Oracle DBA for the foreseeable future.
Sure, if you're learning SQL or a technology to market yourself, Oracle DB might not be the best time investment. However, if you're already an expert in that, you shouldn't have trouble finding a role somewhere.
Lol my company is paying a fortune to get off oracle. Anyone that does not need the million features that come with a oracle will eventually move off it. It's way too expensive to use in smaller environments or non mainframe environment's. Oracle has some of the worst pricing and sales techniques.
Sure, if you're learning SQL or a technology to market yourself, Oracle DB might not be the best time investment. However, if you're already an expert in that, you shouldn't have trouble finding a role somewhere.