IRL meetings are important - but you don't need them 3 days per week. My team has found meeting once per month, or even once per quarter is highly effective. We get together all day, have plenty of whiteboards, and even some team games. We make it fun and productive. It has been working extremely well.

We even fly in the folks who are truly remote - they don't live in the same metro area or even the same state. It's still a lot cheaper and more energy efficient than commercial real estate.