One of the interesting motivations for wanting the extensibility that sidechains provides is to be able to make that zero trust a reality for more bitcoin transaction types.
That would be great, if it was possible. However any given sidechain will always require more trust than the main chain. I don't believe the white paper made the claim that sidechains will be zero trust, did it?
The worst case scenario for sidechains is that they are used as an excuse to keep Bitcoin's transaction rate capped forever.
That would be a best-case scenario to me (with the caveat that I would accept a modest and simple increase based upon quality forward looking analysis.)
Relatedly, and even more importantly, it would allow Bitcoin core to basically freeze as a codebase.
As an engineer, I appreciate well constructed, well documented, and elegant code. Also as an engineer, I've lived with utterly shit code (often enough of my own creation) because of priorty and risk profiles, and because it worked for it's intended purpose and was reasonable well understood.
I was a fan of alternate implementations in earlier phases of Bitcoin's existence. I even provided modest funding to the guy who was dicking around with an erlang implementation/joke. Times have changed, and a realistic expectation of sidechains are THE main change. This relegates the need for experimentation and elegance to the dustbin.
Based on the composition of the Blockstream team, I feel pretty safe assuming this is a goal which they will actively pursue.
Likewise, and I think that is a great thing. This because they are, as best I can tell, experiance professionals many of whom have fought in the trenches on the right side of the historic battles. Fairly demonstrably so. To a large degree their instincts and mine seem to align on a lot of fronts and this one in particular.
In that scenario we do, in fact, end up replicating the legacy banking system. There will be a real Bitcoin which only a privileged elite can access, and the rest of humanity will be relegated to transacting in money substitutes.
Wrong again Bob. With sidechains, native Bitcoin is available to
anyone who wants to pay what it's worth.
Anyone! What you want is to model the ubiquitous welfare state structure that abound with plebs being subsidized by powerful institutions who leverage economies of scale to drop their own costs while milking the herd for different kinds of value streams.
What I see sidechains doing is giving everyone the opportunity to enjoy the kinds of freedom that current Bitcoin allows, but in an honest and robust manner rather than in the sneaky subsidized manner that logically must be the end-game when trying to make native Bitcoin be the one-size-fits-all solution under anything remotely resembling the current system of support.