Interesting.
I always use bags and a longer steep. My water is RO filtered. It produces an acceptable cuppa, but there again I use a splash of milk and don't favor it straight up. So there is that.
My one UK mate always makes loose tea and when I've visited him there's a je ne sais quoi to his tea that I've never been able to replicate. And this goes for several locations he's lived in while I've visited him over some 38 years. I've got to think he's on to something!
Cheers,
RR