The lost art of simplicity
The best art is created during times of stress: wars, shortages, social upheaval, revolution.
Under those conditions people tend to focus on what's important - survival, love, getting enough to eat. Come the "good times" those same people are more concerned with obtaining more, conspicuous consumption, building their dream castles in the air.
Mainframes tended to focus the mind. They had limitations that today would be considered impossible to live with (yet we did, and did very well) - partly because modern O/S, anti-virus, GUI, IDE and monitoring
bloatware software sucks up almost all of the available processing power and system resources. Luckily modern machines are sufficiently powerful that they can push through these huge overheads.
We also had much simpler systems on mainframes. I recently saw the design for a multinational's new customer / call agent system - it filled a wall of A0 sheets, taped to the inside of a"fishbowl" meeting room. It only had to support a few thousand users and (maybe) a couple of billion records - things that a moderately sized zSeries use to do on its own.
The difference is that this "modern" system needs to be web-accessible (with all the security overheads that entails), distributed, load-balanced, resilient and will run, I suspect, a rather crappily designed database (that will have it's original clean design mutated into an unrecognisable mess by changes, bug-fixes, new features and expediency). The design also requires a mishmash of proprietary, bespoke third-party and OTS products bodged together into something should nearly work properly.
However, as someone who makes a living from helping companies sort out the fubars, cockups and dead-ends that their designers wander, aimlessly, into I was glad to see the end of centralised, controlled and efficient mainframe architectures and I am thankful, on a daily basis, for all the complex systems that people design today - even though these dream castles are so far outside their (and my) comprehension that there's a lifetime of assured work, just waiting to be plucked.