Well, lets me explain a bit further.
PowerApps is an online service of Microsoft to create small applications for mobile and web. The service is far from perfect but it works for small internal applications because it's easy to work with it.
However... we are talking about Microsoft.
First, Power FX is open source and it is not a lie.
And the third point, "Power Fx is built for low code". 🤦♂️ No!. Power FX is high code in the concept it works for scripting and nothing else much. You can't compile it, you can't create an advanced program with it.
But, there is another point, Power FX is anything but new. I have used it for a couple of years.
If you are used Power Platform then you are found yourself working with the different styles of programming
If a1 is equals to a2, then the variable is equals to v1, otherwise v2.
It is regional dependent.
For example, it is the code in a computer configured with EN-US.
And it is the same code for ES-ES
If you are using Power Apps then you already have worked with it. If not, then why? Power FX is (as of today) used in one application and not in every one of their variants.