I understand. Most of my work is in text, and I'm very used to zooming way in when I need accuracy. Retiring the Magic Mouse was far easier once the trackpad got big.
I really do recommend experimenting with Desktop Spaces whenever you have more than one app open, though. It's more intuitive with a trackpad, but keyboard shortcuts keep it useful on a desktop/mouse combo.
Control Up Arrow to open the main Spaces screen, move your mouse up to the navigation bar to open previews of every space at the same time, click or use Left and Right Arrows to shift between spaces, and click the Plus sign on the top right to build a new Space. Clicking an app on the dock will take you to the foreground window of that application automagically, and on the main screen, you can drop windows on the thumbnails, or drag windows and selections to the left or right edges of your working screen to shift from one Space to another.