But anyway, I'm purposely staying away from discussing politics here since it's pointless, so I'll just share my experience as a public transport end-user, and the rest can fill in the gaps with their perspectives.
Civic and national pride makes citizens (which includes politicians and the wealthy) more likely to care about the actual state of their country. That's what national pride means, as opposed to nationalism, where they are proud without reason. Is public transit guaranteed to be one of those reasons they feel pride or shame? Not at all, but support for it is certainly more likely to come from that than a bunch of nationalists who don't actually feel any shame at failings of the country, of which public transit is currently.
The current Mayor, whilst still a proponent, likely does not use it. A quick glance at the social media that he recieves will tell you why - it would not be safe. He needs to travel with close protection officers.
The reason? He is Muslim, and Britain has become a very racist country indeed. Well, maybe always was, but the likes of Farage and Musk have so emboldened them that there is no longer a stigma.
Conversely, “public” transportation always needs flawless perfect politicians to continue to fund it