On a slight tangent, how feasible do people think it would be to do something like this for bitcoin? If we phased out all addresses except taproot (for example), then there is a privacy increase there not just from the inherent properties of taproot but also by putting everyone in to the same anonymity set and breaking some forms of blockchain analysis, such as change address identification based on matching input/output script types.
That depends on whether wallets use Taproot correctly. Most will probably just set a public key and completely ignore the TapScript, because privacy gains only begin when you have at least two TapScripts.
Taproot is a brick and mortar, but by no means the finished building.