The impression I got was that the problem was not related to php being slow but just a general scalability problem. If go runs it 2x as fast, it will still fail with 2x as many photos which is very common. Maybe as part of the rewrite they will address this but I think photos is a fundamentally different problem to hierarchical file storage that they require being split up like how google photos is not part of google drive despite sharing the same storage usage quota.