I think the term DBA is quite fuzzy.

There are many technical specializations within this blanked title that are widely different in skill set.

Take your pick from this small list for example:

* Administrating the server + backup chain;

* Optimizing systems and individual databases + applications

* Data-modelling / Data architecture tasks for new systems

There are more, but some will be very heavily oriented to keeping a server running and managing backup/restore, while others will be exclusively development side or troubleshoot side.

As for becoming obsolete...data is the lifeblood of companies, even modern societies as a whole when economically viewed. As long as is stays this way and people do not become mentally extremely capable (trough augmentation or accelerated evolution), information technology jobs will stay. People that understand data and/or how to handle it will be needed. Same goes for programmers which also got declared soon obsolete many times over.

It is pretty certain that for a long time to come, information technology jobs will stay in demand.