I learned to drive manual when I bought a manual transmission car and had to drive it home from the previous owner's house. It's really not a difficult skill. But people look at me as though I'm a wizard when I'm driving my own car. It's kind of crazy.

It can be picked up rather easily in a modern car, sure, but I'd like to note that not all manual transmissions are the same. As in, to drive many of them well, it does take a patient instructor and diligent student to understand the fundamentals, timing, muscle coordination, etc. To your point, yes, everybody can probably do it, but can they do it well?

The test I grew up with was a 1991 Ford Ranger, V6, 5 speed manual. The clutch engagement was extremely narrow and the V6 was kind of underpowered, especially with the A/C on in Texas, so learning how to make smooth take-offs was very difficult. I wasn't allowed to take that truck out on my own until I could drive around a passenger with a cup of coffee, not to the brim but definitely there, and not be rough to cause a spill. It was a high bar in my opinion.

Years later, my VW GTi 5 speed and clutch felt like an absolute dream, buttery, easy. Learning on the much harder transmission, in my opinion, was beneficial.

Yes some older cars are I imagine were rely hard.

My mom is totaly non car person, but in old days she had a car with non Non-synchronous 1-st and 2-nd gear. And she managed to figure it out and drive it.

This sounds hard to me :)

It's not hard if the car has plenty of low end torque (e.g. turbodiesel) but yeah, learning in a peaky naturally aspirated sports car can be a handful.

It's not the torque, tiny euro TDs make no power under 2k, where you'd be lifting off the clutch, but they have absolutely massive flywheels and vague clutches that make "just kind of dump it" a viable strategy.

I'll take driving my 8000rpm sports car over my old TDI any day.