I think the key point here is not whether Google is abusing its effective monopoly willingly, its that it exists at all. There may be alternatives, but not viable ones. Try not supporting Chrome or ignoring Chrome requirements such as security mandates, you will go out of business. You can say these are 'good' for the consumer but the fact that Google has the ability to unilaterally change the web itself is partially…
Or you can not base your business on the fickleness of Google's search algorithms. Ben Thompson (stratechery.com) posts one article per week publically and charged $100 a year for his newsletter. The only time he gave numbers, he has over 2000 subscribers.
There are other ways to build a business that don't depend on search.
Whats the viable alternative to Adsense? Especially when it comes to many Geo's that are hard to monetize.
If you are in a certain niche, find a publication or a podcast that serves that niche and make a direct connection to them. Marco Arment - a one man development shop - created his own podcast based advertising platform that is doing well.
What's the viable alternative to Android
The viable alternative to Android is...Android. Many companies are forking the AOSP version of Android and running their own services, including Amazon in the U.S. and a few companies in developing markets.
The danger Google faces is not that a company will come up with a better search engine, it's that people will start using search engines less as mobile takes over along with digital assistants that give you the information you want.
Facebook is already seen as a place for old people and young people may have a FB page but they aren't posting to it because their parents are on it.