Microsoft had to have a browser choice screen the first time you tried to use IE: https://en.wikipedia.org/wiki/BrowserChoice.eu
And if that actually restores competition then you don't need a five billion dollar fine.
That's basic proportionality.
That is entirely tautological. It omits the reasoning under which that spectacular amount of irreparable damages have actually occurred to consumers.
"They have a lot of money and we would like to have that" is not a valid method of calculating damages.
the fine has been calculated on the basis of the value of Google's revenue from search advertising services on Android devices in the EEA.
In other words, Google had an unfair advantage for search on android devices and leveraged that into revenue. The fine is a percentage of that ill-gotten revenue.
There’s an official guideline for calculating damages when anticompetitive behavior is found: https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:52...
"They have a lot of money and we would like to have that."
The actual "damages" have nothing to do with their total revenue, only the revenue incident to the behavior in question, which is an independent value and not a percentage of total revenue.
For example, if they improve their search engine which causes more people to use it, it doesn't change the actual amount of damage from separate actions -- it may even reduce it by transitioning some of the defaulted users into users who would make an affirmative choice in their favor -- but it would have increased the amount of the fine when calculated as a percentage of revenue because it would have increased their total revenue.
If the revenue related to wrong doing is in the billions and the harm is in the thousands, attempting to prohibit the conduct instead of imposing a small tax and using the money to compensate the victims is obviously a large dead-weight economic loss.