I can't really speak to my productivity in concrete numbers but I feel like I'm more efficient and definitely happier working from home.
I have a job with an hour-long commute each way, up an interstate that goes through a city. You can imagine how I felt about that. I was tired all the time and there was never enough time after work to feel like I was able to do anything. During busy periods, if my boss wanted me in on the weekends (salary, so no OT) I had to put in another 2 hours of driving beyond whatever I needed to do in the office. When covid started, I had just finished a horrible project I felt completely untrained and unprepared for, but which my boss felt I should have been able to figure out. As a result of this, I was put on probation, and as a result of probation, my request to WFH 1 day per MONTH was denied as they "couldn't trust me to get work done remotely".
Well.
In the 10 months I've been FT WFH, I'm off probation, my relationship with my boss has improved (their management style has changed a bit too), I received high praise on a project I worked for in another department, and all of my other work is getting done on schedule. This is in addition to me being much happier because I don't have to deal with traffic, spend $$ on gas, I get more sleep, I can wear casual clothes every day, and I see my parents much more often because we live fairly close to them but I never had time or energy while commuting. Even in the winter I can go for a walk after work and it's light out! How awesome is that?
I didn't eat out at the office, since why would I spend my dining budget on a work lunch? Now that we see my parents more often, and they eat out a lot, I feel like I eat out more than I otherwise would. We've also made a concerted effort to support local restaurants, so there's that too.