Disclaimer: I'm a Debian developer.
My own experience is that things can be broken for months in testing and of course good luck finding any help when that happens. For example, since the freeze for Buster I had broken sound drivers for a couple of months until someone else found that it wasn't actually the drivers but another broken package that as of a month or so ago still wasn't fixed (but the problem had been reported)
That's been my experience with testing for the last 3-4 Debian releases: it works great... except for a handful of annoying bugs that seem to linger almost until release. And assuming you know exactly which package is broken (which can be difficult to narrow down for driver/system level issues), you may or may not get the problem addressed in a timely manner. Then there's also the case of the occasional package that you depend on that disappears from testing for a month or two for any number of reasons.
I had the _exact_ same problem (the issue ended up be a MIDI program called timidity). The main problem for me was that Debian doesn't give any advice on how to report such issues (the website is firmly planted in the early 90s), and the mailing lists I found all appear to be dead. I wish Debian had a slightly more modern website.
What other options do I have if my criteria are:
- rolling release
- not Arch
As far as I can tell, Debian testing is still the least headachy way to get a rolling release, with the added bonus of out-of-the-box compatibility with most of the "we support Linux!" software that only ever gets tested on Ubuntu.
During my ten years (five release cycles) of using Debian testing, there hasn't been an update that required get-out-the-recovery-disk levels of surgery to fix. All of them have been minor user-facing software bugs or package version inconsistencies that could be safely ignored until I had the time or the inclination to investigate. But yes, you do have to be willing to poke around a bit, and not everybody likes that.
But this is why I wanted a rolling release in the first place. I prefer to do minor repair work on a regular basis (but on my own schedule) in order to avoid major repair work every 6-24 months (on somebody else's schedule).
I also don't really mind the investigative work when something goes wrong, since it forces me to learn more about how my system works, and that knowledge invariably ends up being useful later. Some people absolutely hate this, and they would probably be better off using something else.
Like all rolling distros, it's best to be a bit technically savvy and know your way around the distro to handle those glitches. That's the big interest of stable: no bad surprise. Stability is not just lack of bugs, it's also lack of changes with the unavoidable little regressions here and there. There's room for both stable and current, but it's different and criticizing stable because it's stale misses the point IMHO.
Anyway, I agree with you that testing (and rolling distributions in general) are probably not a good idea for newcomers. For those who like to roll their sleeves and dig in once in a while, and like to learn, then fine.
Also, people usually don't need the latest in all. So stable with a few select up to date packages is usually a very good compromise. Just get the latest for what you really care about, and for the rest the no worry but slightly old is just fine. With flatpack/snapd and each language package manager this mix and match is really easy to do and probably a better trade-off than a rolling distro for many people (but not all, so just use what's best for you).
In my experience, the "here be dragons" description of testing/unstable is way overstated... they're both very reliable. If you install apt-listbugs and `apt-mark hold` anything with bugs that sound scary, you'll be fine.
It seems like a lot of people try Debian stable (perhaps thinking of it as an upgrade path from Ubuntu), are surprised by the ancient software packages, and then look elsewhere. Debian might want to consider changing the recommendations they make for new users. Instead of stable / testing / unstable, they could be server / workstation / testing.
> Instead of stable / testing / unstable, they could be server / workstation / testing.
I would love to see something like that, but I think it would need significant changes to Testing to make it usable for the masses. Some years ago there was some work towards that direction with Constantly Usable Testing, which explains some of the challenges: https://old.lwn.net/Articles/406301/
Debian is great in general but the wonkyness surrounding the freeze period gave me the impression that Debian Testing really is something that should only be used if you are interested in helping Debian produce the next Debian Stable release. Some packages don't get timely updates and are only updated close to the freeze period, in preparation for the next stable release. And during the freeze period itself everything is super awkward because preparing the next stable release takes priority over keeping Debian Testing usable.
If the intention is to be on rolling-release, you might as well just use sid. If you'd rather just be on rolling-release until the stable release is carved out (new features desired, for example), testing is pretty fine since it will transition into being the stable release.