The benchmark is the critical/"very utility" online service should work with a noscript/basic (x)html text browser, then you could add a simple CSS stylesheet for the noscript/basic (x)html CSS renderer (for instance netsurf), then if it is really unreasonable to do otherwise <troll but not so much>you could have an wayland/alsa ELF RISC-V binary running on JSLinux itself running in apple/gogol Big Tech web engines</troll but not so much>.
Don't forget that developping the software of the public web site/online service is not the main activity, timewise... the main activity, and by far, is the permanent monitoring and related development, security wise, and availability wise (in the end, the really really hard part is manufacturing state-of-the-art silicon hardware :) ).