At my work it's pretty OO, with FP used where convenient. People join and start reading/writing Scala with zero experience or training, and it works out OK.

At Stripe, I understand their Scala is pure FP, with the first onboarding docs discussing "What is a Monad". I assume they need more training for people who don't have a pure-FP background, but if it works for them who am I to judge.

My own personal style is somewhere in between, certainly more FP than at my work, but nowhere near as FP as those who are really into it.