I have the same taste in movies as you (awful B-grade or cinematic masterpiece, nothing in between), but I have the exact opposite conclusion regarding movies as an art form being "dead".

Just like with music, the technical barriers to entry to make a film or a song are much lower than before, and the market is very saturated as a result. The issue is no longer "is there enough content that I would enjoy" but rather "how the heck to do I make a choice what to watch?".