The article is riddled with what's wrong about proprietary (nonfree, user-subjugating) software. Paragraph 2 is almost entirely made up of these problems:
"the best web browser" -- has no meaning without clearly identifying the criteria by which one considers anything best, worst, or any rating in between.
"If a friend were to ask me what the best web browser is, I’d answer “Chrome” in a heartbeat, so don’t mistake this as a screed against Google’s browser." -- because any deep criticism of a nonfree browser, or a nonfree browser from a spying organization would, by default, be a "screed"? No respect for freedom of speech here, and that's no way to treat your friends. This line and much of the essay comes off as a way to validate the idea that we need not consider anyone who looks out for their own software freedom, the software freedom of their friends and other computer users in general, or their (very much related) privacy interests. The allowable limits of debate are set: technocratic functionality (such as the effectiveness of an ad-blocker, vague notions of competition and "unhealthy growth" without mention of software freedom are considered right and proper to get into. Please restrict any discussion to such proprietor-affirming ideas. Anything outside these boundaries is "a screed against Google's browser".
"I still see it [Google Chrome] as the most fully-featured and trouble-free option for exploring the web." -- so this further reinforces the above: privacy is not a feature and the loss of privacy (where Google decides how much privacy to grant each user) is not to be considered a "trouble".
Nonfree browsers are unethical and problematic for the same reasons which apply to all other nonfree software: we need and deserve to control our own computers. This doesn't just apply to those who write software, but to all computer users. Therefore we all need the freedom to run, inspect, share, and modify published computer software (software freedom). Users who can't or won't learn to program can either choose to learn or get someone they trust to vet and improve software on their behalf. More technically-capable users can help everyone out by vetting and improving published software for their own sake. They can help their community by sharing their improvements under licenses that respect our software freedom. These are deeper more thoroughgoing reasons to reject nonfree software and run only software that respects your software freedom.