To some degree you can get use Glassdoor with the help of the element zapper from ublock origin. What you can circumvent is pretty limited, but you can at least get a bit of information without jumping through all their hoops.

What that said, I would not put a ton of trust in the reviews section. As people have mentioned, companies can get bad reviews removed, but also most happy employees aren’t taking the time to go submit a review. I use it more to see salary ranges for job titles, both generally and at specific companies. Even that is subject to how honest users are about their title and salary, but employees have much less access to that kind of info compared to employers, so I have to take what I can get.