It looks like you got down-voted but I'm not sure why, because you're technically correct.
Rewind 20 years and YouTube, Facebook, Twitter, iPhones, TikTok, Discord and what we think of as the "contemporary Internet" didn't really exist. Google existed, and even back then SEO was a thing and people were talking about not putting all of your eggs into Google's basket when it comes to your business model (which I remember vividly because I started a business in 2003 running a for-profit website that would continue to exist until 2022).
Fast forward to the present and yeah users are opting in to "platforms" that require accounts that keep content within the walled garden. And Google search has declined in quality so much that I and many others don't use it anymore.
But the world wide web, as a technology that is accessible to everyone, that existed 20 years ago still exists.
You can still build a website
You can still create opt-in email newsletters
And there are a lot more people online today than there were 20 years ago, which in many regards makes it easier to reach an audience today than it did back then... even if how you would choose to go about it might differ because of user behaviour.
It's fashionable to be pessimistic towards the tech industry.. and I myself get pessimistic about it all the time.
But when I look back at the fact that I was able to, beginning in 2003, create an online business that allowed me to work from home and feed my family for 15 years at a time before YouTube existed and when the dominant social media platform was still MySpace ... and now I see content creators getting millions of views and some of them are just talking heads in a bedroom ... yeah the world changed but in many ways it's easier to reach people today than it was before this modern era of walled gardens and a google search that sucks.
100% true.
But we are starting to have the first generation that grew up with Google thinking Google, etc was the internet, where as it's not. The culture of creating more than consuming gave way to consuming content and scrolling becoming the default behaviour that was conditioned into users.
Using a platform is one thing, reducing your platform risk by finding the people who will be your supporters is the real purpose of other platforms in other cases... coming to your platform.
As people start to see themselves as a platform, I suspect this will change.