It’s unclear - competitors rely on 3p cookies, but abuse them. Google getting rid of them in theory levels some of the playing field - smaller companies can compete with larger ones because larger ones can no longer track users across every site where they have a pixel installed (IE fb’s massive advantage of having a pixel on virtually every website means only they know every single site you visit).

But in practice, the engineering lift and complexity of the solutions is absolutely massive, so many companies simply will not be able to play ball. Additionally, because the internet will be more private the sketchy companies doing things like fingerprinting will cease to exist. Google has never said they will kill off competing solutions that are not privacy safe (UID2), but have explicitly said they will stop any fingerprinting, cross site tracking, etc.