lawman I have multiple secondary profiles, which are all empty except one.
This has all my apps installed.
Can you be more specific about why you're doing this? The "isolation" that profiles are meant for probably aren't the kind of isolation that you're thinking.
lawman However, when I go into owner/settings/apps it shows me all the apps installed in other profiles (even though it can't run them).
This is the intended behavior. The owner profile manages secondary user profiles.
lawman I thought each profile was completely isolated from each other.
They are "isolated" in the sense that IPC (inter-process communication; a way for two apps to voluntarily exchange data) is restricted. This is not intended as a security boundary, but a way to conveniently separate different personas.
lawman How can I remove this so owner apps looks like default minimum apps
You can't change this. If you want to have a blank profile, you should use a guest profile or a minimal secondary user profile, instead.
The recommended way to use user profiles is if you have a separate persona (e.g. work, school) and you want to have a separate full suite of apps and data (contacts, photos, files), where you won't need to be able to exchange data.