Your criticism of the linked site is valid. Nonetheless it does list the platforms with the largest number of customers.
I tried Okcupid and the number of people there seems to be quite small compared to these platforms (I did like the flexible site mechanics though). Actually I will try one or two of these paid services shortly.
One reason people might pay for such services is because paying signals that you are willing to invest in dating and by extension the partner. We will see.
A while ago I sat at the community camp in Berlin where the CEO of FriendScoot24 and the CEO of ElitePartner were in attendance. That gave me an interesting perspective into how those sites work.
For them it's important that you pay for the service. That means they have humans reading your messages to check that you don't give the other person your email address in the first message. They also allow you to write messages to people who can read your message but need to upgrade their account to actually read them.
Apart from that I don't want to stop you from ...
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