Hot take: the gi is a tradition, not a skill set
Hear me out. The grips are useful. The friction is useful. But 80% of what makes someone good in the gi makes them MORE vulnerable in no-gi. Roger's mount? Marcelo's back system? Buchecha's pressure? All of it works without a gi. Meanwhile half the gi black belts get cooked in 30 seconds at sub-only. If I had to start over knowing what I know now, I'd do 70% no-gi from white belt. Fight me in the comments.