Hard disagree. I want to interact with the grandma's and family that aren't tech savvy. The Fediverse promise is one where the user has the power. I don't see how Meta will change that. All I see is that the Oklahoma asshole who wants to debate will get ads and I won't. Commerical sponsors of the Fediverse is validation of the idea, so let it happen. Yes, Meta will see my username and will try to make ads happen, but thats not what Meta needs or wants: they need high quality content and will accept that some of it they can't monetize. But if they can monetize those users in their corner, then they see value.
The embrace/extend/extinguish arguments are all FUD arguments. Arguments 2 and 3 boil down to Threads effectively walling off their side, which would more or less mean de-federation. And what happens when your now free Lemmy instances starts requiring you to pay $8/month? Or what if some of the larger instances decide to commercialize and sell data? FUD is not a compelling argument: the same arguments were made about Microsoft and their open source embrace. And there are plenty of FUD arguments to make against Lemmy.
I would argue that federation with commercial entities will make for a better Fediverse. Sure Meta is subjectively Evil, but it's motives are clearer than some random dude's Lemmy instances. And by Federation there is ability to get high quality news, science and technology information. In less than a day, major players joined and were posting to Threads.
The email analogy is a false dichotomy. The reason behind the large email providers is because the cost of the running and maintaining an email server is cheaper than running your own. But you could run a trusted email service if you set up your DNS records correctly.