This is the error - "how you use them is up to you".
No.
You play a game - you sign a virtual CONTRACT with your opponent to PLAY A GAME OF CHESS.
Once you play a game of "let's annoy him by waiting for time to run out for spite" this is no longer a game of chess.
This is ABUSE of the trust that your opponent placed in you by agreeing to play with you in the first place.
It's abuse. The time is not YOURS. It's yours only for the PURPOSE of playing a game of chess.
It does make a difference.
As others have said. That player has 10 minutes, you have 10 minutes. How you use them is up to you. No rules were broken, so no abuse to report...
Yes, it's annoying, and so is loosing to a weaker player. But I'm not putting up a thread asking how to report lower ranked players who beat me
If you've got sounds on, do something else for 10 minutes and keep an ear out in case they decide to make a move. Works for me, and I quite like the short break, seems to improve my game.