@Michael Goff nailed it and I can't really add to that.
Most of the benefits you cite are directly benefits for Apple itself not necessary Apple customers.... and seem to be based on the assumption that Apple's laptop/desktop product decisions are being adversely affected by using Intel chips rather than if they used their own. Something along the lines of Apple saying, "don't blame us for the long upgrade cycle on our laptops/desktops, we'd update the line more frequently if Intel was on the ball".
From my first hand experience I cannot agree with you that
"software conversion is not as huge as it sounds". I'm not sure where you're getting your information regarding "
most Xcode projects are pretty much platform independent" but I highly doubt it.
For me, ARM on Mac would be the final straw that causes me to leave the Apple world. But that's me, and I "think different".