Again, plenty of people meander into polyamory because they are introduced to it by their partners and find it works for them.
Especially because polyamory and open relationships are not things people are told about in the same way they’re introduced to the concept of monogamy. Monogamy is a social given and default. It is not something people even have to question. So the idea that people should just randomly discover a new way of doing relationships on their own without someone having told them is preposterous.
Especially because the very idea of monogamy is something you, myself and the rest of us only know about because it was introduced to us.