The benefit to the developer is that they're a delivery cadence agreed with people outside the team so you don't have to deal with constant "are we there yet" and context switching. Think of the sprint as a tool in the toolbox for managing up/out.
You have to think of Scrum as a self-defence: without something like it, the failure mode is the death-march.
> Overcomplication, with an entire industry of trainers, books, and seminars evolving around it.
That's inevitable with anything successful, though. It doesn't have to be complicated: https://scrumguides.org/scrum-guide.html should be all you need.
> Over time, sprint discipline often deteriorates or transforms into something less Agile.
That's a different problem.
> Lack of relevance for teams practicing CI/CD
This strongly depends on what your definition of done is. I've seen teams who think they're doing CI/CD who just plough features into a "next release" branch that only actually goes out to production once a month, or less. This goes exactly as well as you would expect.
But even in a continuous delivery world, I can still see value in "let's see if we can get X done in the next two weeks" where X takes several deliveries to get out of the door. Theming the work helps reduce context switching within the team.
> The creation of artificial deadlines leading to overtime, burnout, and, eventually, high staff turnover.
If that's happening, it's not the fault of the sprint. The work scheduled into a sprint shouldn't exceed what's actually achievable by the team, without overtime or burnout. If people are regularly and repeatedly burning the midnight oil to hit sprint goals, that's a strong signal that there's something wrong elsewhere in the organisation that needs fixing.
> Inability to handle reality. Interruptions and unforeseen tasks will occur.
That's a weakness, but not fatal. Sprint planning should allow for enough flex to cover some unexpected work. You're right that WIP limits could handle it, but with a sprint at least in theory the idea would be that when something that bad comes up, it forces a conversation with the product owner to scrap the sprint and start a new one. The danger in only handling it with WIP limits is that that conversation might not happen.
I do think the current Scrum Guide has made a major error in characterising the Sprint Goal as a "commitment". For several years it was a "forecast" which I think was far more honest and less likely to prompt abuse.