Tea will taste different depending on what temperature water it’s brewed in, but I can’t think of any reason the water itself would be different.
e: The material of the vessel would matter. Perhaps you like the taste imbued by your kettle, which would be lacking if you heated the water directly in a mug.
It definitely tastes different - flatter somehow. I don’t know why, but it does.
Tea will taste different depending on what temperature water it’s brewed in, but I can’t think of any reason the water itself would be different.
e: The material of the vessel would matter. Perhaps you like the taste imbued by your kettle, which would be lacking if you heated the water directly in a mug.