Delphi made it easy as a developer to add those icons, and they had a nice standard set named for most actions you would want a user to do in a line-of-business

Delphi made it easy as a developer to add those icons, and they had a nice standard set named for most actions you would want a user to do in a line-of-business application UI. Also the hello world apps for Delphi had these icons everywhere so it was "just the way" you built applications using it.