I'm not going to sit here and say private tutoring doesn't work, it does, and plenty of people do well with it. But it's got a few gaps that come up a lot.
One is that most private tutors are pretty nice, which sounds like a good thing but it means they're not always going to tell a student straight up that they're falling behind. In a small group you don't need anyone to say it. You just see a mate understanding something faster than you, and that's usually enough to make you actually try.
The other is scheduling. Tutors have their own exams and their own lives, and sessions move around because of that, which is fair enough but it's not great when you're trying to build momentum before a test. Latitude runs on set times each week, if you've booked in, that session's happening.
And private tutoring is one on one the whole way through, which sounds ideal but honestly it's a lot of hours for not much extra benefit once you're past the basics. The homework help sessions here give you that same one on one style support, work on whatever you actually need, but with the group still around you, so you get both.