Just because there is explosive growth does not mean we are in a bubble, sometimes things grow in value very suddenly due to a massive increase in the utility value offered by the item in question. Cryptocurrency is one example of the latter, the utility of cryptocurrency massively increased in the period from when it was first introduced until now, with smart contracts and decentralized applications being added to the mix, stable coins, ETFs, futures etc. There is no reason to believe this is a bubble.
actually an explosive growth in price is one of the main signs of a bubble in existence. but the thing is that bubbles burst and the market corrects itself. it doesn't mean ALL the rise should go away just because it was explosive. for example if we have $100 rise that leads to a bubble the correction is $20 of that going away not the whole $100 rise. and that is the part that people confuse. they think the whole $100 should go away and price should go back to the initial value for the bubble to stop existing.
although you should not confuse a "bubble" in a real asset like bitcoin with a "bubble" in a pump and dump altcoins. the later is completely fake price so it needs to go back down to initial value. in other words it needs to lose the whole $100 rise to exit the bubble.