I've never tried scoping any of my Semi Autos, buy I do have a 3X scope mounted to my old Interarms Virginia Dragoon SAA in .357 Mag. With it's 7 1/2" barrel, a 100 yards is a piece of cake for that old hogleg, and a fun day to ring steel.
Most of my Semi's aren't readily capable of taking a scope. I don't think anyone makes a plate that can support a scope for any of them, that I'm aware of, so to add a Red Dot or Scope would require s trip to the gunsmith to mill the existing slides or buying an already milled slide. Both are expensive options for this retiree.
Red Dots have their place and I like the two I've got on my AR's, but fine precision isn't what they were intended for. So I do keep a 3 X 9 I picked up cheap with a quick mount for when I want to work on my precision skills.
At 63, I agree, my eyes aren't anywhere as sharp as they were 30 to 40 years ago.