At this point I’m not sure any social platform that launches without an eye towards federation stands a chance, really.
That is a...hilariously bold statement. As much as I would love to believe that, the entirety of the Fediverse comprises ~1% of Threads. Not to mention Instagram or Facebook.
Of course it matters. A new network will have to start from scratch and with the "nobody is there, so I won't join"-mentality, potential growth is severely limited. By implementing federation, you will instantly have a base community to build on.