> but the bottleneck in modern web apps is going to be IO
This is true in some senses, but also, response latency isn't the only thing a web application does or is evaluated by. Many applications have, for example, background jobs, that do arbitrarily complex processing outside of the request/response cycle.
Additionally, people who write web services in Rust talk about decreased memory usage, consistent memory usage, and lower CPU usage. In a cloud context, that can translate directly to revenue saved, by spending less. If that tradeoff is right for you depends on a variety of things, of course. "speed" isn't the only relevant metric that you may want to optimize for.
This is true in some senses, but also, response latency isn't the only thing a web application does or is evaluated by. Many applications have, for example, background jobs, that do arbitrarily complex processing outside of the request/response cycle.
Additionally, people who write web services in Rust talk about decreased memory usage, consistent memory usage, and lower CPU usage. In a cloud context, that can translate directly to revenue saved, by spending less. If that tradeoff is right for you depends on a variety of things, of course. "speed" isn't the only relevant metric that you may want to optimize for.