As far as I can see the question was to just learn Live View, which is fine on itself right? no other reasons needed.
But in the real world this would not even be such a weird choice to do as you will (in most cases) empower a single team (or even a single person) to move across the whole stack again instead of doing handovers to frontend teams. A lot of companies struggle with this (handovers, ownership of both parts of the code). So while I agree this ‘decoupled design’ can give you flexibility, from another perspective it can also give you even more flexibility if it’s possible to keep everything inside one team, 1 repo and 1 language+framework (and have less code, dependencies and less knowledge to constantly keep up to date, easier (and a single) deployment target). That said, the use case should still fit live view, we have to avoid 1 hammer, everything’s a nail . (I believe Chris McCord was pretty clear on this, LiveView vs SPA fit different problems/use cases, but in the majority of the use cases they have seen with their company that live view would be a better fit than a full blown SPA).