“A "toy" could help in all those situations, but only if the "brotherhood of aviation" installs transponders.”
Back in the real world we understand that the "brotherhood of aviation" cannot fit the d*** things. So we work on our lookout and do not over rely on a toy which can only “see” a small percentage of threats. If the CAA come up with a mobile phone size unit with a 10 hour battery life from a built in battery then things change. With current tec TCAS will miss almost all the people who could kill you on a Saturday PM over Derbyshire at 2000 ft. You can either except that and work on your lookout, or decide lookout does not work, that flying is too risky for you and give up.
Rod1