De-facto, but actually counter to productivity, just like open-office. Companies that choose to not do this, will have a per employee efficiency advantage. Big companies may not care just like in open office because the per employee advantage is outweighed by the ability to reduce costs for the space

Not too long after this discussion, a similar thought from PG: https://twitter.com/paulg/status/1295788954353111040. "Possible scenario: It's 2025. The epidemic is over, but most big tech cos are still significantly remote, because powerful employees moved to Jackson Hole and don't want to move back. A startup emerges that's intensely not-remote, and beats one of the incumbents by moving faster."

Open office is the second to last act of desperation.

Hot desking is your CEO standing up and saying "I got nothing" when asked how to increase profitability.

In software, remote work is way more productive in my experience working remotely for the last almost seven years. It's a win win. More productivity and way better working conditions (home office, nice desk etc.). Less hours needed to finish. Easier to concentrate. Easier to deal with bad bosses or co-workers or take time out and breaks during the day. More flexible schedule. Much less stress. The pros go on and on. The only negative for work is promotions and visibility, but when everyone's remote, even that works itself out.

How big are the teams you've worked with? I agree it's productive for deep work and when design is already worked out for large changes or additions, but I've had many people on my team complain that they can't work through a hard problem on a whiteboard with peers or quickly sync up on a design and require more time in meetings to get things done across components/team members/teams. Also not everyone has a dedicated office space at home, those people are hurting and having a hard time focusing in many cases.

We don't need to endlessly increase productivity. The US been increasing productivity faster than wages for decades and it hasn't been good for most people.

I'm not arguing either way for whether "we" need to as a whole, but if you want to get the most out of your team and company (and you should if you're running a startup) I think you should look at in person options again once things are somewhat normal if you want an advantage. Some sort of hybrid office(with dedicated per employee offices)+WFH flexibility is probably your best option.

Is there any evidence to support this?

No. There's not a lot of research into it yet because the ability to work from home is relatively new, but this is literally my wife's area of academic expertise and the research that does exist generally shows that given the proper conditions and environment, working from home can be vastly more productive.