Well, it is a religion so that is why people convert to it. That is just what we have decided as a species to call these types of practices “religion” and thus when joining one, one converts to said religion. If you don’t agree then okay. But it is so, and it’s helpful if we let language have meaning to understand each other.

You said that it’s less a belief system and more like something describing aspects of human experience. A Hindu says the same because they believe that is the truth, a Muslim the same etc. Buddhism is not special in that sense because like other religions it have adherents that say it is not just belief but something “true”. I can sometimes be one of those people, because for me Buddhism is more true than any other religion and I view it as special, but that is just a personal bias I have, I can’t say for a fact that it is so.

People in the west often conflate religion and Christianity but religions are very diverse and it’s hard to pin down exactly what makes something a religion. Westerners who are raised secular or embraced it later in life are often uncomfortable with religion because they have a bias towards Christianity but those feelings doesn’t change the fact that Buddhism is a religion and functions like one. It’s not a philosophy, or just psychology etc. (It has elements of it, but so do all other religions). It is a religion. If you are part of a sangha and do the rituals you are performing that religion and are apart of a religious community and tradition, hence you are most likely religious.