I'd be shocked if 10% of users only use EC2. And as you say, for the most part I expect these to be pretty small fry users.
I've used dozens of VPS providers in my life, and a sizable majority had not advertised any load balancing offerings. I can open tickets to move IP addresses around. But that takes time. And these environments almost always require static configuration of your IP address, which you need some way to do effectively during your outage.
Anyone who declares managing their own stuff to be easy is, to me, highly suspect. Day 0 setting stuff up isn't so bad, day 1 running will show you some new things, but as time goes on there's always new and surprising ways for things to break or not scale or not be resilient or for backups to not be quite right. You talk about employing people to manage for you, but one to three persons salary will buy you a lot of elasticache and rds. As a business, it's hard to trust your DBA's and other folks, to believe the half dozen people really have done a great job. Where-as you know there have been many people-decades of work out into resiliency at AWS or others, you know what you are getting, and it's probably cheaper than having your own team for many many people.
I want to be clear that I am 100% for folks buying hardware and hosting themselves. I think it's awesome and wild how good hardware is. But what we run atop is way way way too often more an afterthought than a well planned cohesive system that's going to work well over time. Thats why I am hats off to the open source platform engineering works out there. I think we're getting closer to some very interesting spaces where doing for ourselves starts to be viable, in a way that's legitimate & runnable in ways that everyone-figuring-it-out-for-themselved of the past was always quite risky and where the business as a whole or external systems reviewers rarely had a good ability to evaluate what was really going on or how trustworthy it was.
I aspire for us to outdo the perception that other people managing for us is a great freedom. I really long for that. But the kind of "meh it's not that hard" attitude I see here, to me, dissuades from the point: it undermines how hard and what a travail it is to run systems. It is a travail. But it's one that open source platform engineering is advancing mightily to meet, in exciting & clear ways, that the just throwing some shit up there past always made murky.