Emacs 29 is the current stable release, adding major features: Eglot LSP client, Tree-Sitter language parser and
package.el package install from Git repositories.
Building from source is a convenient way to try Emacs features in advance, especially useful for those maintaining or developing new tools on top of Emacs.
Emacs 29 Features
Emacs 29 - what to expect - a brief summary of the major features