It doesn’t matter if you paint lines on the tarmac. It doesn’t matter if you make the vehicle 100 m long. It doesn’t matter if you cover the wheel wells.
If it does not run on rail tracks, then it is not a tram. It’s a bus that you have given a fancy name, and some proprietary characteristics that causes vendor lock-in.
The defining characteristic of a train or tram is the fact that it runs on rails. With the exception of a few-rubber tyre ones, that means steel wheels on steel rails.
Rubber wheels on tarmac makes it a road-going vehicle, like a bus and not a tram. That means you actually just have a bus with the weight of a tram, which will lead to increased road wear, tyre-wear, particulate pollution, etc.
Compare this to a tram, where the bogies and bodies are designed to distribute the weight properly, and the steel wheels on steel tracks allow for smooth operation with minimal particulate pollution and track wear.