The difference between the QBism and Copenhagen views is quite subtle. There's a technical difference and a philosophical difference. The latter you discuss in the video, so I'll only mention the former.
Basically Copenhagen truly just interprets the formalism, i.e. takes Hilbert Spaces, wavefunctions, etc as a given and provides rules for reading the mathematics conceptually.
QBism wants to reverse this and provide a set of concepts and propositions from which one can derive the mathematics.
In this sense it is part of a line of work called the "Reconstruction of QM", attempts to explain why this particular mathematical structure, rather than interpreting that structure post hoc when it is handed to you. There are quite a few reconstructions at this point, some Bayesian, some Information Theoretic, but they have many lessons/insights in common. If I were to try to paraphrase it in philosophical terms they all say:
"Quantum Theory is what mathematised epistemology looks like when certain weak ontological assumptions are made"
If it's any use:
The difference between the QBism and Copenhagen views is quite subtle. There's a technical difference and a philosophical difference. The latter you discuss in the video, so I'll only mention the former.
Basically Copenhagen truly just interprets the formalism, i.e. takes Hilbert Spaces, wavefunctions, etc as a given and provides rules for reading the mathematics conceptually.
QBism wants to reverse this and provide a set of concepts and propositions from which one can derive the mathematics.
In this sense it is part of a line of work called the "Reconstruction of QM", attempts to explain why this particular mathematical structure, rather than interpreting that structure post hoc when it is handed to you. There are quite a few reconstructions at this point, some Bayesian, some Information Theoretic, but they have many lessons/insights in common. If I were to try to paraphrase it in philosophical terms they all say:
"Quantum Theory is what mathematised epistemology looks like when certain weak ontological assumptions are made"