You're setting a very high bar there, and then claiming that losing access to your gmail account isn't worse than that therefore it's not life changing.

Email ends up being the form of online identity for a lot of people, myself included, so that almost every service that I sign for has my email address as ID. If that email address isn't the ID, it's the preferred way of resetting passwords. I wouldn't be super happy about Facebook being my online ID, nor my cell phone number (see SIM swapping problems).

It's life changing in the same way that losing all your personal documents in a fire sets you up accounting nightmares. Moreover, you're making very light a situation about losing all your pictures. I'm not talking about food pictures, but there's plenty of "me" that's contained in being able to look at pictures of important events of my life (which is why I don't rely only on cloud backups for that).

I don't know what's "life changing" to you, then.

I do have a lot of stuff that I’d be sad about if lost on Google. And yes, I would be inconvenienced to contact all the services for an email change. But when talking about how our society got to where it is now, I just can’t see the moral weight of these kinds of monopolies in the context of just losing access.

I lose track of things easily. Gmail is my brain dump. Not only does it track all sorts of important email exchanges, but it also acts as a dump of scans of important documents. I have several gmail addresses so it's not completely single point of failure, but if my hub email was disabled, I am in a world of hurt until I sort things out.

Should I diversify? Probably, but that's more things to secure and keep track of.