Okay .... not everyone Wants to spin at 90 or 100 rpm. As I stated elsewhere (I think) my Cannondale tourer has 48-38-28 rings and a 14-34 cassette .... and at 48x14 I definitely want taller gearing sometimes ..... because I have to spin faster than I prefer to get to the speed I want to travel. Not sure why this would be a difficult concept.
For most people 48x11 is all the gear they would ever Need to go fast, and few casual riders would ever "spin it out (hit 120 rpm or something.) It is all about comfortable range, and power vs revs.
The biggest difference, IMO, between the 1x with a huge pie-plate is that very few riders are going to climb hills that demand that gearing .... maybe if they ride gravel, and are climbing a sandy or gravelly hill. On the road? Most riders get by with 34x34 and never even use that much.
The double up front and the tighter cassette gives a very wide range of gearing (32x32, like 34x34, is One-to-one, which is a Low gear unless you climb mountains a lot, in which case you'd build big legs and lungs and it would still be a low gear eventually.)
What the double and the tighter cassette gives you is more usable gears, with less jump between gears. This means that it is easier to find a "sweet spot" where the ridder is spinning as fast as she wants and pushing as hard as she wants and traveling the speed that she wants. With a 1x, there are huge jumps between gears, so if one gear is just a little bit too high or low ... the next one is Much too high or low, instead of being almost just right.
1x is fine for off-road where you don't want to lose the time and momentum shifting the front ring, and where efficiency is lower already because of changing surfaces, softer surfaces, and generally more terrain shifts. In my limited experience, when riding off-road there are a lot of times when I would rather push really hard up a short hill and spin really fast down the backside, rather than shift a couple time on the way up and a couple more on the way down, because I have more than enough to worry about, picking the right lines, maintaining traction, jumping up bumps .... and after blasting down the far side there will be some more humps and bumps and sharp turns and soil changes coming up in rapid succession. I have plenty to do besides trying to find exactly the right ratio.
On the road, I might shift for a very slight, 30-foot incline because once I find that sweet spot of revs and pressure, i want to stay there. Sure, I could just power up the incline .... but shifting is so quick, and the ratios are close enough, that one quick click keeps me right where i want to be.
This also matters a lot when either carrying a big load, struggling home at the end of too long a ride, or facing a stiff wind--or any combination thereof. For me, sometimes finding just the right gear makes the difference between being sore and tired, and Really suffering and being miserable.