When a developer leaves, who supports the ETL process? The DBA of course. Guess what, the last dev put Python scrips in the SSIS package and now they are failing. Did you know there were Pythons scripts there? Do you know what __init__(self) means? OK, maybe you know some of that, but are you ready to be a Full Stack Developer? Sometimes one chooses that path, but more often than not (I would assume) one falls into the path, hopefully not falling down too much along the way.
I’ve spend most of my career with MS SQL, but I’ve branched out along the way. Some Delphi and .NET development here, MySQL and Oracle support there, toss some Citrix and Windows administration in too for good measure. I honestly believe the best way to support a system is to know as much as possible about the whole framework supporting an application. Is that always possible? No, but a jack-of-all trades can be extremely useful. Would I like to experience working with experts that can hand off well crafted solutions that I can trust? Would it be nice to be able to rely on my co-workers when problems happen? Of course I would and I still get that, even when we all are spread out over all the levels. Every developer or engineer that I’ve worked with has floated between levels, but still has a specialty where they excel at over others in the team. Even in places where devops is the norm, due to preference or budget/staffing requirements, there will be specialization and no one will be an expert at all levels. I have yet to see the Full Stack person that beats out everyone else around at all levels. I also haven’t seen a Sasquatch, but I’m not ready to give up on them either.