Yes, ignore all ratings and read the review content. You can spot pain points, such as missing remote-flexibility, or bad incentives, or impossible deadlines, or bad equipment, or lousy onboarding, micromanagement, meetings late in the day, racism (like in Tesla factories)..

Reading reviews helps you understand what you should pay attention to. You might take some things for granted that the company completely violates.

You can then use your knowledge to ask specific questions during the job interview. Like: "What's your remote work policy and please put 5 days at home in my contract." Or you could spot the open office with old computers.

As Tolstoy put it: "All happy families are alike; each unhappy family is unhappy in its own way" And it's up to you to spot a specific unhappiness at any given company.

Yes. I treat Glassdoor reviews the same as I do hotel reviews or restaurant reviews - look at the reviews where people are positive but have criticisms, and look to see if those criticisms have a trend in the reviews (or if some reviews even tell people that thing is a positive - "difficult work life balance" "high pressure rewarding environment)

If they're all positive (or negative) then that's a sign there's something wrong.

Yes, especially non-engineers, like everyone in my family. It's why every HR I've encountered has asked employees to put a positive review on the site

Yes, I mostly look at critical reviews and really pay attention to things mentioned by a few employees in different words. I usually do this while interviewing, so I am only interested in the negative takes as the company will readily tell me every positive aspect they can boast of.

Just apply a bit of common sense to the comments and they will be a great source of insight. Some things they say can even be verified elsewhere (like if people from management keep getting into harassment lawsuits, if the company mistreats its clients, and similar).

I think the only reviews I somewhat value are Steam reviews