That is so true. But I find that 'local' tea brands are sometimes a tuned to characteristics of the water supply, e.g. last year on holiday I St Ives, I found 'Cornish' tea much better there than when using the few bags that we brought home.Woah. Woah. WOAH!
There is a world of difference between Yorkshire Tea and PG Pi$$/Tetley.
In my teens I did a Saturday job in a local J Lyons teashop, eventually rising to the status of operating the tea counter. Now that tea was really good and it wasn't available to buy and take home. Joe Lyons was universally known as the place to get a reliably good cuppa.