This could also be big for web UIs which leverage server-side rendering. I've been ramping our use of blazor server-side for web interfaces, and putting an application server in one of these local zones near where we all work/live could have a really positive impact on perceived performance.
Right now, I ping ~50ms out to us-east-1 and things feel "pretty good" in our server-side web UIs. If I could drop this by a factor of 10, we are getting into gaming monitor latency territory, and pure UI state changes could be resolved in timeframes that would be perceptually instantaneous for most users. I.e. things like clicking a button to pop a modal you wouldn't even worry about trying to make a client-side interaction anymore. You'd just wire it up using some trivial @if(showModal) inclusion block on the server-side html page template.
Granted, this imposes a pretty harsh geographic constraint if you have just the 1 server, but it is likely feasible to separate the view layer from your persistence/stateful layers, so you could host your view rendering services in multiple local zones, with all the business logic and state kept in one of the primary regions. Not all things can always be instantaneous, but if the UI is highly-responsive there are countless UX approaches for indicating to a user in a friendly way that they simply need to wait for a moment. Being able to build your web UI around blocking calls into business logic seems like a powerful place to be in terms of simplicity and control.
Right now, I ping ~50ms out to us-east-1 and things feel "pretty good" in our server-side web UIs. If I could drop this by a factor of 10, we are getting into gaming monitor latency territory, and pure UI state changes could be resolved in timeframes that would be perceptually instantaneous for most users. I.e. things like clicking a button to pop a modal you wouldn't even worry about trying to make a client-side interaction anymore. You'd just wire it up using some trivial @if(showModal) inclusion block on the server-side html page template.
Granted, this imposes a pretty harsh geographic constraint if you have just the 1 server, but it is likely feasible to separate the view layer from your persistence/stateful layers, so you could host your view rendering services in multiple local zones, with all the business logic and state kept in one of the primary regions. Not all things can always be instantaneous, but if the UI is highly-responsive there are countless UX approaches for indicating to a user in a friendly way that they simply need to wait for a moment. Being able to build your web UI around blocking calls into business logic seems like a powerful place to be in terms of simplicity and control.