Perhaps a new "Use smaller elements in Animation Editor" checkbox in Preferences? or a way to resize the side border by dragging, and as you increase the size it would increase the elements size as well? (But this seems a bit hard to add, especially because the tools would need to be repositioned to the center)
Anyways, I think this might be late to add into Fusion now, especially if it's the resize by dragging method, (or maybe not, only Yves knows) but yeah they are very small, I'm personally still not all too comfortable using them, but I guess it's just a matter of getting used to the smaller size
And btw increasing the font size does help (Windows scaling too)