Well, of course; why would you want to keep the initial clipboard forever? This is exactly the same behavior as for ^C/^V. I don't understand the purpose of your question.
Imagine you install a 'clapper' in your bedroom to control the lights. You say "works great for me, let's install this everywhere". Someone responsible for an auditorium then says "so clapping turns the lights on and off?"
That said, I frequently use text selection as a highlighter. I will highlight lines as I'm reading text to help me keep track of which line I'm on. I also need to select text to apply formatting such as bold or add link.
Imagine you install a 'clapper' in your bedroom to control the lights. You say "works great for me, let's install this everywhere". Someone responsible for an auditorium then says "so clapping turns the lights on and off?"
That said, I frequently use text selection as a highlighter. I will highlight lines as I'm reading text to help me keep track of which line I'm on. I also need to select text to apply formatting such as bold or add link.