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.
The first thing I need to make clear is that ETH is not a shitcoin, it has utility and is used by a lot of other projects as a development platform, ETH is really cool. Second, whether ETH or another altcoin surpasses Bitcoin, I will still use it. Bitcoin has always had a big influence on the crypto market and has a very popular support community. I believe that in the near future, it will be difficult for an altcoin to surpass Bitcoin