Yep - ESRI is using the transition to AGOL/Portal/Pro to remove Open-Source options from the backend database stack. This will force you into the walled garden.
PostGIS is a joy to use in ArcProducts before Pro. There is a reason it is becoming a global standard for geospatial databasing (including spatial geometry intrinsic functions and indexing).
PostGIS is still the best option, juice your ArcMap installs until ....
will there be options for backend database usage for AGOL/Portal/Pro?
It doesn't really matter what the average salary is. Are graduates able to get jobs? That's what really matters. If you can't get hired after 4 years of college, it was a waste of time and resources. From what I can tell most GIS programs just don't cut it. Mine definitely didn't. What's the point of wasting 4 years and tons of money if you're just going to have to learn a bunch of new sht when you graduate? I honestly believe that GIS should not be a college major.
or rather, the programs should be adapted to include all the "new shit" you'd have to learn
Developer here who has risen through all the BS and become a GIS developer. I have managed enterprise databases, got companies onto arcgis server, worked with open source web mapping applications, done imagery and lidar analysis, and worked with multiple utility networks. That was all great.
My problem with GIS is that in my view, especially looking towards the future, is a complementary skillset and not a career path. To advance, you usually need another degree and/or be constantly willing to learn new things on your own time. That's how I became a developer. Want to manage ArcGIS Server? You should probably have some background in computer science, networking, and security. Want to manage SDE? Better know sql and have some good database skills. Want to be a GIS analyst? Stats would definitely help, as would more knowledge related to the field you are analyzing, possibly even geomatics. The problem with these things is that if you are competent in that other area, you can likely get paid more by dropping GIS from your job title, but if you aren't competent there, you aren't really competent at GIS either.
I actually do appreciate this perspective... but to me what you're describing is both a blessing and curse of GIS. It's ridiculously broad. I tell people all the time, that I used to want to be a meteorologist (weatherman) growing up but then when I got to college, I realized I was more passionate about the environment so I graduated with a B.S. in Env. Sci. and since landing myself in a GIS job I tell people I could be a meteorlogist, environmental scientist or anything in between - haha
But all jokes aside, I have to concur that yes that is a drawback of GIS field is that to get to the next level, like you have, it requires you know more than sheer GIS/Arcmap functionality. You should supplement it - but to me, as I alluded to earlier, that just shows how powerful and robust the tehcnology is, that it can be used in so many different capacities. GIS when paired with something else can make it more powerful