How people spend their monies is their business. However, if the physical media business goes away because the studios are not making enough of a profit then that's that.
People buying physical media only when it’s on sale at 40-50% off are not helping the survival of physical media because the studios aren’t making a huge enough profit margin to make a difference to their revenue streams. George Feltenstein has noted that reality a few times during The Extras...
More like wishful thinking! If the studios are cutting costs by reducing the number of titles available to streaming, why would they expand disc releases which are more expensive to produce and release?