What would happen if I lost my card (down the line when you are a bank)?

That would be great too & I expect it’s something that Monzo’s considering. Jonas described this process recently, which included a mention of virtual cards -

& the fraud team are big fans of virtual cards too so I expect we’ll hear more about those, once the current account have launched.

From there it’s very easy to imagine a similar process to the one that you & Jonas have described but for replacement virtual cards which could be loaded into Apple / Android Pay while you wait for your physical card to get to you.