With homebrew, I never know how many packages will be updated and how long it will take, so sometimes when I just need a small utility, suddenly it'll update a bunch of packages and it takes 45 minutes.
It's a UI problem.
I'd add that script-y usage of brew already can block on user input (e.g. if a cask asks for sudo), so adding a go/no-go check probably only breaks the most determined automators, while the benefits accrue to a wide swath of users (both new and fat-fingered).
Regardless, thanks for all the work you (and the community!) do on Homebrew! I wouldn't like macOS half as much (or have bought half as many) without it.
brew outdated will list outdated app/dependencies that need to be updated. If you want to know the app's dependencies, use the info argument. For example brew info ffmpeg will list the information about FFmpeg and list the dependencies that it uses along with status indication if the dependencies is installed or not.
Am I missing something here? I am not sure if it is a UI problem since Homebrew have those functions with a few arguments here and there. Look like you are using a utility that have so much dependencies that it needs or you have habit of using brew upgrade which will prompt to upgrade everything expect pinned apps/dependencies.
Yes. The principle of least astonishment.