i've always said that when it comes down to federated server pegged SC's, go right ahead. it doesn't change the protocol so i don't worry.
It can be the leverage that causes the protocol to effectively change by replacement of Core. A pegged side chain that is undeniably
superior to Bitcoin Core could suck all the
BTC out of Core and that pegged side chain could have the spvp implemented. That isn't a guarantee of it happening, but from my perspective the odds are quite high. One of the attributes that raises the odds of such is the resistance to changing the protocol of Core. Thus any undeniably superior tech is unlikely to be politically implementable in Core.
I repeat that a consensus algorithm which can't be 50% attacked has an even better odds of catapulting Core, because it won't be vulnerable in its infancy.
This journey has been like playing a strategy game. I've thoroughly enjoyed it.
this is where you are so wrong!
what is superior? Bitcoin is not defined by a hierarchy of superiority, its defined by a juxtaposition of incentives that create a network of people that benefit from those incentives and so the tool is created it's spreads natural like a virus. Those who see value in the tool can use it those who don't use other tools like fiat, alts or gold or whatever they think is hierarchically superior.
the only reason a "superior" sidechain can exist is because the incentives inherent in the Bitcoin protocol have been changed and a bigger network of users could by some engendering supersede Bitcoins network in size, the result is if that were to happen yes all the Bitcoin value would be sucked out.
So superior is defined only as something all those non thinking masses you want to heard believe is better, it doesn't have to be better in any way that's important to me, in fact by your definition of "superior" could even apply to an inflationary sidechain that is followed by the economic majority, with a little manipulation from TPTB, bitcoiners would move there bitcoin over just to survive.
if you want to test whether or not your idea had market appeal use a Spin-off, if you want to co opt Bitcoin and leverage its first mover advantage promote centralized development and Sidechains. The problem is your competing with the actual TPTB for the succeeding SC, not the free market.