Mindfulness meditation may reduce stress levels, but only temporary. Instead of focusing on the source of stress and trying to solve the underlying issues, it fights the symptoms. I don't say that it doesn't "work", but one should be aware of the limitation of mindfulness practices, and look at it just as one of the tools in a tool set to fight stress, not as a holy grail, like many of its proponents preach.
User counters 13000 word meta study by simply stating the opposite without giving any arguments, sources or studies. Is there a forum like Hacker News, but with no "talking out of your ass"? How could the mechanics of a forum be set up to achieve this? The thought "Is it a long term effect or just temporary?" is totally fine. But then just posting out of your ass does not help anyobody. A quick search for "months" in…
This particular one does a lot of math which no one has the patience to verify. It just sounds smart, like the papers on nature.com that advertise probiotics.
If you trick yourself into being happy while being exploited by the system it may indeed work (that's why rulers liked Christianity as a tool for pacifying the masses). But you are not solving the underlying issues.