If I would have time to invest into this I would try following:
- fork the existing OSM Carto project (create a new style based on it)
- making distinct brand-new style is likely going to face a bigger problem with final step
- preferably find another person/people interested in improving it
- implement some changes, maybe like this busway one
- propose replacing current OSM Carto by new style - though I admit I am not entirely sure should it be directed to OSMF, website maintainers or general OSM Community
- asking gravitystorm to kick out existing maintainer and becoming maintainer of gravitystorm/openstreetmap-carto project is I think a worse idea, in multiple ways
I would give decent chances of success of it replacing current OSM Carto, though it depends on how it would be executed. Also, may be made irrelevant by vector-based map.
There may be a better way to achieve this. But either way you will certainly get some drama and uncertainty about outcome. I would not do this if someone deal poorly with drama and politics, especially if they tend to generate plenty of either.
If someone is interested in this but dislikes uncertainty and politics adopting HOT map style is also possible.
But I suspect that not a lot of people are actually interested in being a maintainer of such style. I used to be one for some time and right now I am not willing to spend my hobby time on that.