Games for Windows Live—Microsoft's ill-fated PC equivalent to Xbox Live's service—stopped receiving updates way back in 2014. Many games pulled out the discontinued service splinter early, while others dragged their feet. Seven years later came the kicker: in 2020 several of Capcom's games were made unavailable on Steam, thanks to the scraps of Games for Windows Live code which were actively breaking them.
The games impacted by this—as highlighted by user DedSec_Pearce on the PC Gaming subreddit—are Lost Planet 2, Lost Planet: Extreme Condition Colonies Edition, Resident Evil: Operation Raccoon City, Street Fighter 4 (though you can purchase the Ultra edition, which still works fine), and Street Fighter X Tekken. If you find their Steam pages, you'll see the following message:
