Most languages end up needing a way to step outside that language, and if you don't have macros you end up using something even worse. Rust in particular lacks "do notation" or proper support for higher-kinded types, so it needs to use macros as an ad-hoc replacement for things like sequencing async operations or proper propagation of errors. To be honest I'm surprised they didn't find a way to make a web framework in plain rust though.