I believe you need to own the app to review it, so there is a cost to consider. Maybe it’s freemium or just a dollar but regardless you need to create an account, buy it, review it,…
Barely any apps get you to pay upfront any more, in my experience most are free to download and it's either a trial, or so ad-ridden that it's unusable without an in-app purchase. Either way, any account could leave a review without paying.
if your app is just a dollar or two like most are a couple grand to pump the reviews seems like a no brainier