No for many reasons.
I’m an anxious person. I’m a person with fairly low self esteem. If my partner were to see someone else I’d take it upon myself that there would be something insufficient with myself that my partner had to seek in someone else.
I couldn’t imagine myself looking for another. Relationships are hard work with just a singular person. It’d be stressful to spread myself out with multiple people.
Poly relationships seem like just a miscommunication away from an utter meltdown. People who think they can realistically workout are kidding themselves.