There was a golden age when computers were something you owned, not like before when they were big machines your employer or university would give out access to, nor like after when they went to the cloud, you bought what was essentially a thin client and every software became a service.
At least in the olden days the computers weren't forced into every single damn part of society!
Now in order to talk with most of your friends and family, you have to sell your soul to every one of the thousand ToS's. It's impossible to meaningfully use your personal device you bought with your own money without the internet, as every app and their mom needs to call home for some reason. For some reason, it is morally acceptable for a company to prevent you from being able to have someone you pay to replace parts of your device with third-party components you bought with your own money!
Now, of course, you can simply install some Libre operating system and use Lemmy, or Mastodon or whatever. But computers are so embedded into society that it is simply impossible to go without these services unless you want to get yourself isolated (and potentially in trouble with the authorities).
Besides, from prior experience, most people are unwilling to use technologies unless it is physically placed in front of them, whether through social influences, advertising or word of mouth, which generally corporate services do better than Libre alternatives.
It used to be that computers and programs were made for the end user. Now they are simply tools for ad and data-collection companies to extract every byte of personal data and force every second of advertising on others.
I've been seriously considering to remove computers from most aspects of my life, but as paper slowly disappears from our lives, this becomes harder and harder. Now you would likely be fired if you refused to use Teams or Slack or whatever your company uses. No one uses fax or writes mail or watches live TV anymore.
The only other alternative is to take back computers and make them personal again.
There are plenty of options for personal computers; you have to make the choice to go private and personal.
I built my own desktop, which remains very common and is relatively easy to do. I have Linux and Windows on it, and use Linux nearly 100% as I agree I don't like ads etc. I use a Firefox with ad blockers and don't get ads; I use lots of open source software even to access services like Youtube (Free tube).
There are also even linux laptops, and the Frame.Work laptop which is fully modular and bring your own OS.
There are open source OS for phones.
You're right about the corporatisation of the internet and services, but it remains up to users to vote with their feet and chose to take back their privacy and person computing.
Linux is at 4% of desktop users in recent months - that is many millions of people actively choosing to exist in a space where they control their personal computers. People don't need to remove computers, just chose to set them up to be what they want them to be.