With the release of macOS Sequoia, macOS Monterey will probably lose support in Homebrew, while machines running Monterey, that cannot be upgraded to a newer macOS, are still great development machines.
The developers of Homebrew have opted for a development strategie, that forces Homebrew and all applications installed with it to stay at their most up to date release. Enhancements and security patches are therefore continuously applied to Homebrew and all applications installed through it.
Homebrew can be used to install applications, that are already part of the macOS installation, but are installed by Apple in an older version. Homebrew is therefor a way to keep a development system continuously up to date. This is an important step, because Homebrew might be used not only on secondary computers but to install and maintain critical infrastructure software, such as database servers, web servers, application servers, programming language version managers, etc that run the internet.
That said, it might be useful and part of sustainability to use hardware for longer than Apple would prefer, just like OpenCore demonstrates.
Homebrew supports the last three versions of macOS. Older versions (currently back to El Capitan) are unsupported, but may work. This means that an update of either Homebrew or Homebrew-core, the formulae repository, might result in a non working environment.
How can I use pin, tap and --build-from-source or other solutions in order to keep using Homebrew after they drop the support of the version of macOS that I am using?