How much time does an only child need to play with friends

My 9 year old son is always asking to play with friends. He says he’s lonely. We home school, so his interaction is limited to our homeschool co-op (Tuesday) and Sunday school. On Monday, Wednesday and Friday evenings, he has swim training with other boys his age but it’s not free play, nor are they allowed to chat in the pool. Growing up, my husband and I had neighbors to run around or cycle freely with every evening after school. Neighborhoods were much safer then. But we live in an increasingly dangerous neighborhood with more homeless people and drug addicts coming into our area. I’ve noticed he has a hard time playing, negotiating or accepting no answers in groups. This is why he prefers playing one on one with friends who will follow his lead and add their own input to the games he suggests they play. How much time does a social 9 year old boy need to be with friends his age? A boy in his co-op has told my son he doesn’t like him. What do we say to my son on how to deal with this boy? How do we teach him to negotiate? I’ve tried and tried to arrange for playdates but it’s been very hard due to the PNW city culture, distance or schedule matching. Should we move to another neighborhood with more children? We then struggle with the fear of what kind of children our son will have to play with and this is an expensive solution to the problem. We do note that he interacts with adults confidently and with little reservation if he deems them safe. He can even lead a conversation on topics he enjoys like WW1&2; Lord of the Rings etc. Is it more valuable he has free play and freedom to be a 9 year old with lots of play, or more valuable to speak with and learn foundational truths at a young age around loving adults and skip the turbulent adolescence stage? Thanks so much Nicholeen.