My point is that we need time and patience, not interfacing with Meta. Whether they use ActivityPub or something proprietary shouldn't matter to us and I'm not convinced matters at all in this context.
Meta already didn't wait - they have Facebook, Instagram etc. There's Twitter. We already exist in a space with big competitors, and somehow it works. Inviting them to our space sounds risky (risk of centralization, ads, bots, rage bait for engagement...).
If our thing is better, more wholesome, with less ads and bots, it's going to attract the people we want on our platform, regardless of whether or not we federate with Meta.
Plus, as was already said, fediverse success should not be measured by how many people use it. If enough do to produce good content and engage with, that's great on its own :) Small communities have benefits.