I don't think _won_ is the right term. _In the lead_ would be a better phrase in my opinion. I think Planetscale being based on MySQL will hurt them in the long run. Tying themselves to Orcale is already hurting them, having to fork MySQL to add vector support for instance. Neon, on the other hand, gets to benefit from a larger and much more collaborative community in Postgres, as do other Postgres vendors like Supabase, Azure, AWS, Tembo, Nile, etc.
Please continue to use the vendor that you find works for you, however.