The next problem is, even if by some miracle of gawd this actually did happen, you would be degrading all credibility of your own crypto as a store of value at the same time. If a random turdcoin could pass or even get close to Bitcoin, it would mean that at any time your new coin could just as easily be overthrown and go to zero. This means the only logical move is likely to go with BTC or just stay out of the game period.
I've never understood this line of reasoning. If an altcoin passes BTC in marketcap, it, by definition, *won't* be some random altcoin, it'll be a legit altcoin. You seem to be begging the question by describing it as a "random turdcoin" passing or even getting close to Bitcoin. If it passes Bitcoin it'll be the rare, legitimate altcoin, not some random one -- one that actually offers something valuable that Bitcoin isn't offering.
So, it actually *wouldn't* mean that at any time this new coin could *just as easily* be overthrown and go to zero, because it *wouldn't* be easy for an altcoin to pass Bitcoin, and, if one does, it could very well be based on something fundamental as to *why* it passes Bitcoin, and Bitcoin also wouldn't necessarily have to go to zero in the process.