My counter to both points is you'll never know what you could lose until you've lost it, and then it may be too late ever to recover. Ceding control of the World Wide Web, which currently runs mostly on open standards which allows countless people to write software that works for it, to huge private companies brings with it the risk said companies could decide, jointly or severally, that they're no longer going to support features we take for granted. Such as being able to connect with almost any web site we want to. Or sending email, because they decide email's not worth supporting any more.
Control has
already been ceded. There's not a lot I can do about that except, as I said, shout at clouds (lol

). It's done. You lost. I for one have moved on.
Not only that, but there's more money to be made by railroading you into using their proprietary apps to communicate over the internet. Who knows? Maybe the web as we know it could disappear into a GoogleNet and a FacebookNet, and heaven help you if Google or Facebook decides to cancel your account.
I don't care whether companies make money or not. They're turning a profit? Great. Maybe they'll continue to provide the service that I am paying for. If they don't, I'll pay someone else to do it. And if they're turning a profit, and I'm not violating my terms of service, why would they stop letting me give them money? As hypotheticals go, that one's pretty far-fetched.
For me, two cases in point. I used to be able to run an email server of my own, on my IP address, to send and receive mail directly from and to my own computer. I can no longer do that because ISPs have decided I shall not (they block the ports at their border routers) so now I have to pay a third party to host email for me. This despite the fact I have the technical know-how to operate an email server in a secure manner.
Good for you. I have never had nor wanted the skills to be able to do that.
Second, as each generation of gateway device comes to me from my ISP, its functionality gets worse and worse. The latest device I got was so brain dead I had to put it into bridged mode and use a third-party device to regain functionality I lost when they stopped supporting the old device. (Indeed, the term "ISP" is now a misnomer: what they really want to do is simply be a WSP: "Web Service Portal," and deny me access to all the other services available on the internet. )
"Worse and worse" is just a synonym for "different". I have learned to use the tools they provide. When they change the tools, I work out how to use those too, since I neither have nor particularly want a choice in the matter.
What happens when the next device won't even give me a bridged mode? Will I have to shut down my home PBX because I can no longer get inbound SIP connections? Shut down my private NextCloud instance because I can no longer get HTTP/HTTPS packets to my server? Shut down a VNC bridge I built for a third party because I can no longer even ssh in to my own network from the outside?
Probably. I don't have any of that and barely know what any of it even means, so it's completely irrelevant to me. My life is not changed.
Now these example are from the point of view as someone who cut his chops working from the early days of the internet. Most of what I describe are probably out of your knowledge realm and experience, and so of course are not applicable to you. But try to think of other activities you're involved in. Now imagine the entire supply chain for equipment for that activity getting taken over by one or two American companies, who then decide they just don't want the hassle of dealing with Australia. Would you care then?
It already is. It may be news to you, but America dominates a
lot of markets. Given the choice between dealing with America and dealing with China (which are the two options in this part of the world), I choose America.
To me, "it's never been particularly clear to me why I should care" is alarming, because I rather doubt you'd say the same about your Australian government. Am I being paranoid? Well, Americans got a real wake-up call with Trump when he enabled the Supreme Court to overturn Roe vs Wade. Now millions of American women can no longer get easy access to abortion.
Then you should vote accordingly to overturn those governments that are denying people their rights, and encourage your fellow citizens to vote accordingly too. As do I. I lived through Abbott/Turnbull/Morrison, you lived through Trump, and here we both are. They were dark times indeed, but we came out of them, civilisation uncollapsed.
Why I think you should care is that ceding control of the Web—currently in the public domain with open standards—to huge American corporations is that it carries similar risks of reducing your ability to use the web as you do today, and possibly making it impossible to do certain things.
Again, it already is virtually controlled by American companies - if you think the internet is still in the public domain then you are mistaken - and if certain things are made impossible then I just have to live with not doing them any more. Do you think I could
change it? Stop it? What kind of power over American corporations do you think I have? What kind of power do you think
you have? I assure you, Meta and Alphabet are completely ignoring whatever principled but tiny stand you think you are making. It's not a hill I choose to die on.
That's good. But why, given that it's never been particularly clear to you why you should care? (I'm being rather facetious with this question.) What will you do when various powers decide running a VPN is a criminal offense? It has happened already in some parts of the world.
Again, I started using it because it's useful to me. If it stops being useful, I will stop using it. If it's made illegal, I will stop using it. I don't have a choice.
Look, you are free to protest in any way you like. I, personally, don't see the point. The tools that these giant American companies provide are useful to me, so I use them. Whatever data has been harvested on me is already buried very thoroughly in data warehouses, and has been for decades. You too. My life is not affected by it.
So again - it is not at all clear to me why I should care.