By do better, you mean do worse. Take a good thing and mess it up. What you are describing is called a "gadgetbahn".

The reason the trams and trolleybuses work is because they are big and carry lots of people. If you replace them with lots of crappy car sized vehicles then each one needs a separate physical connection to the electricity source.

That number of separate vehicles would very quickly wear through the contact material. Then of course you have other issues. Lots of trams can operate in one lane but lots of cars create congestion and then need multiple lanes, each with their own electrical supply. You will also have issues with connecting and disconnecting rapidly in the case of a potential collisions. Trams and trolleybuses generally don't need to worry about collisions.

Basically the problem is that you are restricting yourself to a specific set of dimensions for your vehicle (about 2metres wide and 5metres long). If you consider vehicles which are 50cm wide or 50metres long, then there are many more solutions.