Bitcoin is hardly in a bubble. Bubbles occur when assets are OVER-valued. Bitcoin continues increasing in price because as it's true value is being determined.
On the other hand, stocks, bonds, fiat money, and numerous other assets are in massive, dangerous bubbles. Whenever I advise anyone to get out of the US$ or real estate or stocks, they reply something to the effect of, "But it keeps rising in price." A classic feature of a late-stage bubble.
As those assets keep rising in price, more and more people jump because it seems like a sure thing. But there's only one thing that they can be entirely sure of, and that's that the insane increases will not continue.
Of course, bitcoin may be in a bit of a bubble, and it will go through corrections every now and then. But anyone who simply ignores bitcoin or any crypto simply because they believe it's in a bubble should take a longer, harder, and closer look.