That's a much requested feature. With imho two main challenges:

1. Much traffic data is private / requires licensing, however some countries have reasonable public data. For example the TraffXML (https://gitlab.com/traffxml) project has some.

2. The project is free to use, but also volunteer driven. It requires setting up a privacy preserving "live data" infrastructure.

If you think this is a nice challenge and you can help, feel free to reach out!

https://github.com/organicmaps/organicmaps/issues/1160 would be a good starting point.