with the caveat being that I came into the industry in 2014 so I may have missed the golden age of the DBA fully - I worked for a DBMS vendor on sales/solutions side for a while and most DBA’s I spoke to were slightly more knowledgeable business analysts. I met very few who really understood IO and Paging and Locks and how they’d impact a DB’s performance. Which kind of makes sense because if you were really obsessively into that you’d probably do something different or you’d work for a business dealing in storage systems. The value a DBA has been very low in my career outside of forcing process improvement just by saying no to things.