> higher number of opportunities. <
Limitting search/result is often used to tease users into the subscription. Eg. Tiner allows in free mode only a certain number of swipes. Is it this what you mean? This is usually depends on: Search + text for free but limited, or "pay for everything" I do not see why putting some features behind a paywall is "against users interest" and how this limits/increases his/her chances?
You are claiming that dating sites should be free - this doesnt work usually (POF as exception) - and making users pay for those does not increase his/her chances: EVERYTHING that happens before you met someone will be crashed usually in the very first second you met (and smell!) someone.
So if you have a chance with another person, is something that is completely(!) out of control of the website operator. EDIT: this is something website operators do know, they cant change it and this is something that they should put on their website - they are selling dreams and expectations, which wont become true in real.
> Eg. Tiner allows in free mode only a certain number of swipes. Is it this what you mean?
Yes. The direct result of this is that other users have an arbitrarily limited number of opportunities to be swiped by you. A few users circumventing this limit (by paying to get around the wall) does not significantly raise this number.
Instead, it makes things worse, because a small number of paying users will get an outsized opportunity to swipe your profile! That's only useful if you are categorically attracted to people who pay for Tinder. Otherwise it is counterproductive to everyone involved.