When you say its a bubble, youre looking at a currency and comparing it to another currency. This time one is a crypto currency and the other is a fiat currency.
If you measure everything in dollar terms only, youd probably think that its in a bubble. But if you ask someone from a highly inflationary country or just any other country - theyd say, to heck with it - Im buying more!
Now, if I had a crystal ball and told you that Bitcoin (BTC) would reach US$ 500,000 or US$ 1 million - would you buy today??
If you stop thinking in terms of one currency against the other, and start thinking in terms of purchasing power - your perspective will change.