You're definitely right that the popularity of DVDs and BDs has decreased. Especially with BD. When Coldplay released their live film in 2018 they only released it on DVD and released the HD digital version on iTunes. There is still definitely a market for physical media such as DVDs and BD's, and I think if they had released Berlin on BD / 4K it would have been profitable, it's just not as big as it once was.
I love the idea of having an ultimate "iNNOCENCE + eXPERIENCE" boxset. This is what I would include in it. I have to tried to keep it somewhat realistic and this product