I agree on some points, but I think it’s not fair to compare it to email. People use emails for work are somewhat forced to use them pretty often. I don’t know anyone who browsed Reddit for work over the past 12 years I’ve had an account, and I don’t believe Lemmy will change that. People are not forced to use Lemmy, reaching the maximum amount of people is usually not the point unless you’re advertising, and if you’re targeting the Facebook crowd you can… advertise on Facebook - this wouldn’t even be anything new.
The question isn’t whether or not the majority of users can use the Fediverse without being hampered by the corpos, it’s whether or not the core users can. Unless Meta can somehow force federation unto all instances, I will be able to choose an instance that is not federated with them.