A web browser allows access to all websites (broad reach). HN is just one website on the web (narrow reach). Pretty clear to me why this is a bad comparison, just interested to know why the OP thought otherwise.
I don't see what reach has to do with making HN "free" and Chrome "not free" if they both use space in their interfaces to deliver advertisements. Arguably, Chrome would be more "free" since HN displays its advertisements more prominently than Chrome's and they masquerade as user-generated content. Is there more to your metric?
Sorry, I should have read the parent post more carefully. However, I still think that's it's valid to compare Chrome and HN strictly on "freeness" regardless of whether or not they're the same kind of product.
We're talking about advertisements and the advertisement's only one one page. The scope of the actual advertisement is roughly the same as it is on HN. The fact that an advertisement in the default tab of a browser is likely to have more viewers is irrelevant.