As everyone said, it's not a degradation of the handwriting but, degradation of attention to writing.
Taking the time, slowing down and being aware of writing immediately resets my handwriting.
Also, the smoothness of the pens affect your handwriting legibility. A fast pen like a Uni Jetstream makes my writing worse. OTOH, a slightly resistant roller, a gel pen or ideally a fountain pen brings out the best in my handwriting.
In my case, I've also just forgotten a lot of my script as I've switched from writing for others to read to my own notes. I never had good handwriting--as I recall it was consistently my worst grade in elementary school but I did know how to make the Palmer script letterforms even if I didn't execute them elegantly. Today I don't really even know them except vaguely.
Taking the time, slowing down and being aware of writing immediately resets my handwriting.
Also, the smoothness of the pens affect your handwriting legibility. A fast pen like a Uni Jetstream makes my writing worse. OTOH, a slightly resistant roller, a gel pen or ideally a fountain pen brings out the best in my handwriting.