Hi. I'm David, and I'm happy to help you.
Windows changes the Scale instead of the Resolution for one main reason: Image Sharpness.
I'll explain why:
Modern monitors (LCD/OLED) have a fixed number of physical pixels. If you lower the resolution to make text bigger, the monitor has to stretch the image to fit the screen, making everything look blurry and pixelated.
Windows keeps your monitor at its sharpest setting (Native Resolution) but tells the system and apps to render text, icons, and buttons using more pixels.
In short, scaling makes things larger while keeping them crisp and clear. Lowering the resolution makes things larger but blurry.
Feel free to ask any questions you may have.