I was convinced my Birks were destined for the landfill, but there are places that can do full footbed and sole reconstructions. I sent mine out to https://repairmybirkenstocks.com/ (Michelangelo was an absolute gem of a person) and got them back a few weeks later good as new! Basically everything is new except the straps. Huge win for sustainability, but also this cost me ~$80 as opposed to $150 for a new pair!