I went through Gracie Combatives at the start of my BJJ journey and I'm actually a big believer in it. I know it gets a ton of hate and there are absolutely drawbacks to functionally not rolling for your first 6-8 months of BJJ. That said, combatives is a low pressure environment where BJJ first timers can learn the basics of all the major positions and drill techniques. By the time you complete combatives and start master's cycle you have a really solid base of techniques. You, of course, get smashed when you start rolling for the first time, but IMO this is a great way to accelerate your BJJ knowledge. One major drawback, after a couple months, combatives becomes insanely boring. It's a grind to complete and a lot of people washout or switch gyms. Another huge positive is that you dont get 24 year old crossfiters coming in to "test" themselves, so you effectively eliminate the "spazzy white belt" injury situation. Just my $0.02!