[shadowgovt]

And indeed, if anything, a project like emacs being unable to make a decision like this results in a project that slowly dies from the weight of its own history.

Tree-sitter is fairly universally understood now to be "the future." While cc-mode will likely have its place for a long time (hard to beat regexes on speed, even if they break down when the input is too noisy), moving the default to the tree-sitter implementation aligns with the other language modes going to tree-sitter. For good or ill, consistency is almost certainly better than new users having to learn "Your code is parsed by tree-sitter. Oh, except your C and C++ code, unless you set this flag, because Mackenzie threw a fit in 2024. That's a fun bit of history you get to care about forever now as a user!"