Eventually most people figure things out and make the most of it in adulthood, but it definitely makes for teenage/young adult identity crises that monocultural people don’t have to deal with.
The former group has more issues fitting in, while the latter seem to be just fine. Certainly plenty of people in Europe speak more than one language natively and don’t feel like they lack a home. And it’s not like there is an actual country where only deaf people exist. So the idea of avoiding bilingualism seems totally absurd to me, especially when probably the majority of the world has some level of bilingualism by default.