Unless the landlord has 100s or 1000s of tenants I don't think people can stay anonymous usually people rent for multiple years the churn is not high enough for deducing who wrote the review
Totally this! In the UK many landlords only have one or a few properties and it would be obvious which tenant is bad mouthing you. In some cases there are laws against "revenge evictions" but I don't know how much people would be willing to get into a shitty situation and trust arguing about those laws just to leave a review.
Never mind that the landlord can probably self-review.