IDK the first bjj place I tried was so gross and intense, literally hazing-type behavior with new people. My current MMA gym has incredibly serious competitors but also grandad brown belts, 30-something hobbyists, and literally children. You can get rocked if you're specifically looking for that but it's very very chill if you're not.

I don't think either of these is representative, but I've come to think no martial arts school is representative. You just got to look around and see what you find.

For sure some BJJ gyms are just as toxic as the OP says MMA gyms are. Some are very heavily focused on competition and train in a specific way likely based on cultural issues imported from Brazil. I think the key is to try multiple gyms (regardless of sport) because there's always a chance the culture at one will be toxic. I love that in my gym you also have the 70 year old brown belt who will smoothly choke you out with very little physical effort or discomfort to the 280lb serious competitor who will also choke you with very little physical effort or discomfort but will also match intensity if you're wanting to go harder. Most of the folks seem to do a very good job of matching intensity. The guys who want to roll hard and fast as they are preparing for a tournament have all of those opportunities, but they also realize they are in a gym with a bunch of filthy casuals like me. I've never felt in danger because folks want to go all out. Brand new white belts are the most dangerous folks in the gym.

I did decide to try to keep up with my training by dropping into a class while traveling for business. That's where I got a bruised rib and had trouble breathing for a couple weeks because apparently there's some ego thing involved in putting visitors from other gyms in their place. I just stick with the place I know has good respectful folks now.

The BJJ gyms near me (I live in OC, it's practically the BJJ Mecca -- one of my neighbors is a head professor at the Gracie HQ in Irvine) just aren't that great for busy parents. Classes are at absolutely shit times if you need to help with your kids on either end of the day... 7am or 7pm. If you work and can't get away during the day, you're SOL.

I haven't been to a BJJ gym since before the pandemic because the one place with night classes (9pm) shut down and the professor left the state for economic reasons.