And good luck installing and using most mobile apps or doing mobile payments without being trapped into one of the duopolists ecosystem.

In the US if you want to watch the Olympics what company do you turn to? Well the only option is NBC who paid 7 billion for exclusive (US) rights, so you're turning to NBC. Other companies could and likely did bid, but NBC paid the most. Even worse there are no (legal) alternatives.

How about your local sports arena, school campus or restaurant? Do they serve Pepsi or Coke? It's not always cash but they might have bought (or discounted) that soda machine with the big PEPSI logo on the side, or the scoreboard that says COCA-COLA.

If I search for "shoes" on Bing the top result is Temu, are they monopolizing Bing Search?

Just because you pay doesn't mean it's a monopoly. Google pays Apple $20 billion per year to be the default. Microsoft can afford $20 billion, heck they can afford $40 billion, why aren't they paying?

In terms of switching, you said you switched Safari but that didn't update Siri. That sounds like an Apple bug to me. If Google is forcing/threatening Apple to make a worse product, that's a case of them being a monopoly.

In terms of Assistant, that is part of Google Search. On my Android phone I can choose a different default "Digital Assistant", in my case I can pick Firefox, but it looks like others exist in the wider ecosystem.

If you're saying Google Search should be separate from Google Assistant, I think that's a reasonable request, but not doing so doesn't make them monopolistic. Looking online, since I don't have these assistants/devices, Siri can be charged by changing Safari (which I know you mentioned was an issue for you earlier), but Alexa will only use Bing (unless you use some third party stuff) and I'm unclear about Cortana but Microsoft gave up on that so we can ignore it.

I do agree I would love to see more open and accessible APIs for all these different services. I should be able to have Apple iMessage on my Chromebook and Chromecast on my Apple TV. I think there is a lot that can be done to improve things, but what I'm not convinced of, yet, is that Google has been monopolistic. Obviously the case is ongoing, so I look forward to more information.

As for the Microsoft CEO, it's clear to me he wants to be the default without paying for it. I won't fault him for that, that's $20 billion in savings.

Google is monopolistic now, but they didn't BECOME the biggest search because of it, obviously. They became the biggest because they had the best search engine, then leveraged it to become what they are now.