Free on Rockstar's new launcher: https://socialclub.rockstargames.com/rockstar-games-launcher

Honestly, as great of a game that is, I don't consider it enough to get yet another launcher(especially one for devs who hardly have any PC games to put on it). Just buy the Steam version.

I hear the latest Steam update broke the game

Only thing I heard about that was that the latest update(years ago) removed some radio songs and added controller support. That wasn't Steam's fault. Apparently the license Rockstar had with those tracks ran out so they couldn't sell it without removing the songs. Going to a new platform won't change that. They'd have to renew the license if they wanted to keep the songs.

Getting the Steam version lets you "downgrade" to an earlier version that doesn't have those changes and where most of the mods work.