In the 90s and 2000s, software came with a bunch of features that most users would want, and also a few small but powerful features that a tiny portion of their users ("power" users) really cared about. Almost every software had "power" features of some kind. A config file, command line arguments, that kind of stuff.
Nowadays, popular software like Chrome are all too eager to drop "power" features; to make themselves simpler. This avoids confusing general users, at the cost of alienating "power" users.
Dropping Ctrl+tab (heck, making shortcuts support a low priority) is one of such features.