You say that, but based on the current utilisation and the way that stuff goes across Norwood Fork / Gloucester Road, I believe paths were identified for an additional 2tph, but were never used due to the performance risk. The suggestion was always that when LO went to 20tph on the East London Line it would be 4tph to West Croydon, 6tph to Clapham Junction (although I think it was conceded 2tph of those would be Battersea Park) at peak, 6tph to Crystal Palace at peak and 4tph to New Cross.
That said, the only way to maintain suitable capacity was to have at least 2tph from London Bridge to Norwood Junction stopping, and the 2tph from London Bridge to Victoria.
Obviously things have changed and now the levels of capacity we needed pre-COVID have been amended, and you’ve short-sightedly had a government bin off the 455s, but the service cuts that are in place are excessive and savage.
The South London Metro area has undoubtedly been shafted in all of this.