The length of time people have been ignoring something doesn't affect if it's real or not. A phantom center channel is a cost optimization, and in many cases it

The length of time people have been ignoring something doesn't affect if it's real or not. A phantom center channel is a cost optimization, and in many cases it's good enough, but it's also true that many people have trouble hearing dialogue in movies. Some of them will benefit from a real center channel. How much they'll benefit depends on the acoustic environment and listening position. This isn't a new idea; the very first movie with multi-channel audio used a real center channel: https://en.wikipedia.org/wiki/Fantasound https://en.wikipedia.org/wiki/Fantasound