There is a lot of shilling lately (again) with "the flippening" event happening. Ethereum has created a new market which is basically 99% scam tokens, rugpulls, pump and dumps and NFTs which are probably used for money laundering. Anyway, the thing is, there is definitely if a demand for all of that, even if it's all based on a platform that's not decentralized.
So to the point: Would you quit if a centralized shitcoin managed to surpass Bitcoin in marketcap? At that point it would be clear that entire space is a joke. Bitcoin would still march on as usual, but it would be just sad to see people putting their money on shitcoins rather than on the only actually decentralized blockchain worth anything.
If there would be some flippening then for sure people would really do on what they are seeing on the market which they would really go into majorities decision because we know that whenever something new that do happen into this market then its just normal that people will follow.
If ever that bitcoin had been overtaken then that would really be an unsure thing on what would be heading next but for sure there would be major changes on this market behavior.