I'll put it this way, I lived in Hamburg before the current apartment, and we got the very nice apartment there even though we didn't have an application portfolio with us for the viewing appointments...
We didn't have an application portfolio either. Why would we, I never intended to make myself appealing to anyone. It's about a business, not about offering yourself personally to someone.
But we had dozens of viewings, including some houses we would have wanted, unfortunately others always responded faster than we did, so we didn't get the properties.
At one "mass viewing," it was even the case that one interested party immediately committed and the sellers were also totally surprised because then some others directly expressed their interest right after. We left the viewing immediately back then.
I see it now with my sister's house as well. There is a family who really wants the house, but unfortunately they were later than those who have now been awarded the contract.