https://www.theverge.com/2023/7/26/23808274/meta-microsoft-amazon-overture-open-source-mapping
Watch out, Apple and Google.
It seems they consider themselves complimentary with OpenStreetMap, as stated on their FAQ https://overturemaps.org/resources/faq/#
Overture is a data-centric map project, not a community of individual map editors. Therefore, Overture is intended to be complementary to OSM. We combine OSM with other sources to produce new open map data sets. Overture data will be available for use by the OpenStreetMap community under compatible open data licenses. Overture members are encouraged to contribute to OSM directly.
I don't know a lot about any of both projects, but it seems fair.
All companies are forced to play nice when they aren't at the top. Google has a monopoly on mapping, their only real competitor is TomTom, and really only in the US. All of these companies need mapping data and don't want to pay google for it, so it makes sense to work together to release this.
It makes sense; OSM is a great source of mapping data, but it misses POIs like businesses and whatnot. If I understand it correctly they all want to chip in to make a huge combined dataset that has the potential to rival Google Maps, especially if they all use it and allow people to contribute as easily as you can do on Google Maps.