What will happen if crypto vanishes overnight or due to some or the other reason if crypto becomes inaccessible to public? I know this does not make sense as crypto will not vanish but still what if it happens? What about those huge chunk of investments made by whales and other investors?
This only happens if crypto has absolutely no use-case, which we know is not true. Prices fluctuate, they fall as well as rise, but I can't see that some new as yet unheard of technology will suddenly render all of crypto obsolete.
The reason we may worry that prices will drop to zero is that the markets are so speculative and so dependent on consumer confidence, but that doesn't mean it's 100% speculative. Crypto fulfils many real needs, and has many genuine reasons to exist.