Ideal reality: Google doesn't buy advantage from browsers to make their search engine the default. This way, other search engines can compete at the same level, right?
Reality: browser developers will have their income cut down because now their main source of income is dead (see recent news on Mozilla).
Usually these kinds of policies that may or may not come up out of goodwill results in unintended consequences that negatively affect others.
The winner here are the politicians.
Limiting the number of homes people can own will reduce the incentives for people or real estate developers to build more. You may end up with lower supply of homes, which may drive up price.
Modern economies usually depends on economies of scale to make profits. Imagine if a law was passed to limit the number of groceries people can buy in a supermarket because the government think it'll help poor people by hoping the law will drive down price. This would probably backfire, prompting the supermarket to buy less from distributors, and sell at a higher price because now they can't count on economies of scale.
In short, I'm saying your solution is naive.