Can Blockstream’s pegged sideschains solve Bitcoin’s modularity problem?

Towards solving Bitcoin’s modularity problem, Blockstream CEO Dr. Adam Back alongside Matt Corallo, Luke Dashjr, Mark Friedenbach, Gregory Maxwell, Andrew Miller, Andrew Poelstra, Jorge Timón, and Pieter Wuille proposed new technology, a pegged sidechain. According to a white paper, the pegged sidechain would enable Bitcoin and other ledger assets to be transferred between multiple blockchains. This would solve what Adam Black calls Bitcoin’s modularity problem. It is difficult to introduce advanced or experimental features directly into Bitcoin for risk reasons. I could see that it was a very valid concern. So I moved onto the next problem how can you