Found this article and considered it worth sharing - although data from 2023.
It is the view of locals about their capitals' public transport - maybe also interesting for travelers. I liked the interactive horizontal bar chart.
What was your best or worse experience with local public transport in Europe?
What did you like / dislike?
In Germany travelers are sometimes confused in which city they need to validate tickets. From overall feedback on the Germany forum I would say that the D-ticket is a real value for travelers.