I thought this was already known? I can’t recall exactly but there was some research pointing to SSRIs in general as not being particularly effective at all. They were just hyped a lot and became mainstream.
I wouldn't go that far, but there was a now-famous study (Princeton?) that showed that doing aerobic exercise for maybe 30 mins every day, about five days per week, was equally effective at alleviating depression symptoms.
There's one big problem with that - getting seriously depressed people to do 30 minutes of exercise (or anything else) five days a week. "Get more exercise" is excellent advice for someone who feels a bit down, but it's absolutely useless for someone who can barely summon up the strength to eat or brush their teeth.