A hacker that was able to hijack the mining pool just for malicious reasons could do it. Maybe they are motivated by not liking Bitcoin energy use.
The better argument here is that 98% of cryptocurrencies are very cheap to 51% attack, and they are attacked successfully. One would expect these to be exploited aggressively before a successful Bitcoin attack. Hints of unmanageable abuse would be exchanges de-listing alternative cryptocurrencies due to mounting losses.
The bottom line is if Bitcoin can't survive a 51% attack, then everything else below it is non-viable.
Personally I think the gaping vulnerabilities of altcoins and the scalability of Ethereum is a bigger issue than what may happen to Bitcoin over the next decade+. Major catastrophes with any of the other stuff could go a long way toward causing loss of trust, interest, and value in Bitcoin.
The better argument here is that 98% of cryptocurrencies are very cheap to 51% attack, and they are attacked successfully. One would expect these to be exploited aggressively before a successful Bitcoin attack. Hints of unmanageable abuse would be exchanges de-listing alternative cryptocurrencies due to mounting losses.
The bottom line is if Bitcoin can't survive a 51% attack, then everything else below it is non-viable.
Personally I think the gaping vulnerabilities of altcoins and the scalability of Ethereum is a bigger issue than what may happen to Bitcoin over the next decade+. Major catastrophes with any of the other stuff could go a long way toward causing loss of trust, interest, and value in Bitcoin.