Smartphones doesn't replace computers though, every office worker needs to know how to use a computer since computers has an inherently more powerful UX. Smartphones has simpler UX, but computers has a more powerful UX.

Applications being able to assume that you have a keyboard, mouse and big screen really allows them to create way more powerful interactions while any tool made for a smartphone will be severely hampered by its UI limitations.

> every office worker needs to know how to use a computer

Exactly, so more people than ever know how to use computers.

Not sure if that is a joke or not. But if it isn't I think you greatly underestimate how many knew how to use a computer 10 years ago. Office workers aren't a big enough share to say that more people than ever know how to use a computer.

What category used to have a computer 10 years ago but doesn't now?

10 years ago people used computers for things that they use smartphones for today, like doing banking etc. So the category is everyone who feels they need a smartphone today but doesn't feel they need a computer today.

Assuming this is true. What is the benefit to society or individual of blue collar workers owning computers in order to do online banking?

Seems like a great benefit that they don’t have to deal with all the unnecessary complexity.

Being forced to learn enough computers to log on to your bank doesn’t make you more employable.

Take a small example. Is Figma replacing photoshop for designers? Is Google Office replacing MSOffice? If these were to fully replace their local counterparts, then they would also obsolete the whole concept of navigating a file system as well.