People leaving M+ runs needs to seriously be addressed

Yes, many, many, many times before.

Thank you for adding to the number as it approaches infinity.

What I would propose is that you form a group of people you know you can trust to do certain things, and play with them. Whether it be a community, a group of people you just know or a guild party. Which is basically how it was intended to work best.

However, it seems they are aware of player concerns, going by this: