> my arch installations tend to be quite lightweight.
That may explain why you don't get that many problems.
If you start pulling in many different components, the set of potential interactions grows exponentially. And if you add to that external software, it easily becomes nightmarish.
I've seen other comments saying that they've been running Debian or what have you for years without any upgrade hickups, and personally I've never had that.
The easiest way was always to simply remove as much as possible, start the upgrade, and then pull back whatever I removed, so that the system setup would correctly fall back in to place. And even with that, I sometimes get problems.
The main issue is probably not that upgrades are issue-less. The problem is perhaps the lack of cooperation between distros so that everyone could benefit from the experience others built along the way. But How does one organize that sort of cooperation?
Or maybe there's too much friction between distros and upstream developers?