"unnecessary and unproductive pressure "
Isn't this, candidly, the whole reason for sprints? To keep up the deadline pressure so everyone is always behind and it's easy to intimidate people into working 60-80 hour weeks?
Let's not go along with the pretense that breaking complex projects into manageable pieces originated with agile or scrum; that's how we worked 30 years ago. As with those silly neologism (stories, technical debt, refactor ...) agile claims credit for things it didn't originate.
In 1989 I put in 60 hour weeks at Microsoft because I liked how they treated us: free stuff, catered dinners, private offices, stock options. Later it changed to working man-killer hours out of terror of the annual review and only the free coffee remained.
After working on Vista and having a few nervous breakdowns I promised myself to keep it at 40 hours and if they didn't like it they could take it up with the kiss-up/kick-down managers who promised insane delivery dates based on trade shows.
You're a smart guy, Maarten, you can see what's happening here. The methodology thing is revealed as the collection of absurd fads that it is. It's breaking down. Groups are abandoning agile.
Throw it all away, go back to enabling unbroken concentration, watch productivity soar like it used to.