Some of the factors people using dating site usually consider good vs. bad:
Good sites tend to offer:
Real profiles with good verification / fewer bots.
Features that help filter by what matters to you (age, location, values, etc.).
A user base that matches what you want (age group; serious vs casual; niche preferences).
Good safety / privacy practices.
Reasonable fee structure: free or with premium add-ons, clear cancellation policies.
Good UX (easy navigation, responsive support, meaningful matching tools).
Bad sites often suffer from:
Lots of fake profiles / bot/spam accounts.
Hidden fees or confusing subscription/pricing structures.
Poor customer service.
Bad matching algorithm or too superficial (only looks/pictures matter).
Privacy concerns or safety risks.
Not enough users in your area, or mismatch between what the site is good at and what you want.