We had the same issue indeed. Eventually we had to do a workaround where
we stored certain data on a profile level (create a field and use
'update profile' in journey). Then you can use that data in marketing
campaigns, bit ugly, but it works.
Our client has the use case that they want to send a promotion/email to
their top 1000 customers with the highest customer value. We can do the
aggregated sum of all values to generate the customer value, but we
don't see the possibility to select 'just' a 1000 profiles, is that
correct? We've tried...