If you’re going to take that view, then you need to be comparing the BART system to the entire London Metro system (The Tube, overground, Lizzie line, and suburban rail). There are many services that run parallel to the Lizzie line in central London. But they don’t share track, because that’s a terrible way to operate a metro service.
If you take that approach, then BART looks like a toy compared to its equivalent in London.
If you take that approach, then BART looks like a toy compared to its equivalent in London.