To be fair that is sort of the point of traditional currency. It gives everything a value to make bartering easier, so if you are a pig farmer you can easily carry a couple of pigs worth of value around with you without actually having to carry a couple of pigs. Also makes trading half a pig a lot easier too
So if we value everything in Sterling, then BTC is just bound to get sucked up into that framework.
While bitcoin is unstable, it won't be used as a reference though. I was told about 20 years ago that in Russia there were financial problems such that the standard currency in Moscow became the subway token. No matter what happened to their currency, a token was always worth one ride on the subway, so had a fixed and tangible value that everything else could be compared against.