I kind of have a bit of both mindsets. My soulmate and I had experiences together that were really unusual and magical. So in that sense it feels like destiny. Also from a determinist perspective maybe it was. But the actual maintenance of the relationship requires effort.
So the discovery part feels like destiny but the maintenance part requires effort, although the effort is not onerous, more just consistent habits of behaviour and consideration.
We've been together more than 7 years btw. We were friends before we dated, but the "destiny" feeling came after some really profound experiences on psychedelics.