I think the taste thing is interesting.
I can tell if you put fresh water in the kettle, or reboiled it.
I always only boil the right amount, and always empty the dregs and put fresh water in before I boil it.
I can also taste if the water is no longer boiling, so the kettle boiled 5 minutes ago.
Also if someone puts the milk in before the teabag has finished brewing.
I can taste all these. I'm really not bothered at someone esle's house, but I home I want freshly boiled water at 100 degrees.
So, I really do think that the water from a hot tap tastes different.
And if it is boiled and stored under pressure , then it does not have oxygen bubbles in it, which is what brews the tea.
So, handy maybe, but to make tea - no.
(and come to that, coffee is better with water NOT boiling, so it wouldn't make good coffee either would it?)