@dbDavid Bushell ☕ just bandage fix (and I'm sorry but will @ you my editor), but VSCode has a setting where you can list filenames which should be considered JSONC (and by VSCode's definition, also allowed trailing commas). that's the reason why it never shows error for trailing commas in tsconfig.json files, because by default it's there.

again, it requires you to set it up, and I completely agree with you that it's painful to work with them, this is more of a "move out the annoyance out of the way" fix 😮‍💨