A couple of other points - gear spacing is a big difference.
A triple is a pragmatic way to keep small gaps between gears AND a big range. Otherwise it's either-or. Probably this matters more riding on the road or with a touring load. Similarly road compact doubles 34/50 have a horrid jump between the two ranges.
Most of all I'm remain unconvinced by the poor chain line running 1x at low gears.
Indeed. Tyre size is more informative but then you have to consider tyre deformation too and it all starts to become very complex. A professional racing team might need that level of detail, however. The nominal wheel sizes are enough to get the general principles though, I think.
@FluffyChicken@hamster I didn't look at 2x mainly because the flat bar gravel bikes tend to be 1x not 2x. However, I would be happy if there were some 2x offerings even though I agree that the change between rings can be brutal.
If I was still mountain biking I'd be happy with a 1x system - I rarely used the largest chainring when I rode trails in the early 2000's because the trails were steep and really rough making climbing gearing more important than descending gearing and dropping a chain was a reality and a hassle.
I'm pretty happy with 2x on my gravel and road bikes for the most part. I am running 3x on a couple of old 7 speed 26'ers and its fine as well as long as I plan for the climbs well in advance.
If your bike can´t have a front derr. then go w/ 1x. Otherwise you pay more for less durability . 1x is not simpler; friction shifting is simpler.
If your bike is a 29er mtb or gravel w/ short chainstays chances are there is no space for front shifting. 1x was made to solve that. A 1x on a 26in mtb makes no sense.
I dont want to get into gear inches, repetition etc. Just a note that I reckon 1x puts too great an angle on the chain. 2x would be better.
When you think about how a 1x chain routes from the ring to what is a gigantic low speed cog. Its angled upwards and far over to the side. To my mind this ,especially with the huge cassettes means the chain is more prone to wanting to come off.