I'm always wary of anyone leveraging concepts such as "investing in mental wealth" or "focussing on self improvement" in order to pander 5 bullet methodologies. Even more so when the author interjects a plug, both shameless as well as irrelevant, for their own book - Beyond Coffee - in their argument.
The fallacy hidden in the article is that each of us is completely in control over our physical and mental well-being. That your well being isn't an inevitability but a choice. If it's a choice, then this implies that making the right choices is 100% your own responsibility.
Sure, the author does raise a number of fair points about mental healthcare and how some good daily habits affect your own well being.
But then the author completely misses the mark in the conclusion.
No two human lives are the same. Everyone's experience is uniquely different and shaped by an infinite number of events and circumstances past, present and future. Most of which humans don't even get to control directly. The idea of controlling your life and the optimistic view that one is able to mould it towards an ideal stems in Modernistic tradition.
Human minds are doing poorly at self diagnosing, while it's very hard for others to spot the signs of mental health issues. Mental health is also deeply woven into the identity and the personality of individuals. Personal struggles are very much part of being an individual.
Rather then pandering "we should invest in our mental wealth" or even "we should go for a yearly mental health check up", start by sitting down and listening compassionately to those around you first, without offering any practical solutions. If someone lost a loved one, they don't want to hear "maybe you should see a therapist" right off the bat, they are addressing you directly, and they hope you're just willing to listen and acknowledging their pain and not much more.
If someone states they suffer depression, anxiety or PTSD, rather then arguing semantics, the more important questions to ask would be: Am I listening to this person, what are they trying to say and do I understand what they are saying?
Finally, statements that start with "we should..." without backing up their claim, tend to rustle my Jimmies. Who's this "we" anyway? And why am I being dragged into the argument from the outset?