I've used Blazor for one project, and it was a true joy to learn. All the good parts of React, but without some of the clunky design decisions that come from having to work with traditional browser javascript.
As you can see in the top banner, it's using the "interpreted" mode, which is the slowest runtime mode for running .NET on mono-wasm. But it's also the "compatible" mode.
It would be possible to produce an AOT build which would be 50x faster, but it's a little more work and it wasn't the goal of this demo.
Will the challenge be that you cannot hook to low enough UI/human interaction events to build an alternative for DOM? E.g. Paste menu is impossible to do (needs CTRL+V in Google docs for Firefox), cannot get information about keyboard typing mode in multilingual setups and so on.
IIRC Flipboard once tried this approach, rendering everything to a <canvas>. As it stands right now, that will never be a viable solution for the reasons you mentioned, along with the fact you throw literally all accessibility features out the window.
