Almost all of my running is done barefoot or in sandals. I race in Altra Vanish-R shoes. I run 80-90 miles per week, usually around 7 min/mile.
It’s certainly an awesome tool for improving your form and foot strength. And once your form is good, you can run in anything. I recommend huaraches, since they give the most freedom. My favorite ones are Earth Runners but there are other good ones from Luna, Shamma, and Bedrock.
You don’t need to run barefoot only on grass. Concrete/asphalt is cleaner and safer, and the hardness makes bad form uncomfortable. Your feet will not toughen up to friction, but they will become more resilient against rocks as they get stronger. If your feet get blisters then that’s a form issue. I also think that, over time, your feet can adapt to colder temperatures...but I prefer Injinji socks + sandals.
Toe shoes are a gimmick. Go barefoot, or use huaraches if you need protection and toe socks if you need insulation.