Great questions as usual, giftedamateur.
In my observation and experience, those who are happiest, most satisfied, and fulfilled in their life find their career to be just one aspect of their overall schedule and self-concept.
Sadly, for those looking for a formula or equation for efficiency and success in choosing a profession, there is not one. There are no guarantees. (Personally, I can think of nothing more dehumanizing than the "guarantee" of being assigned a career path based on a government school's impressions formed early on, in middle school or high school.)
Involvement in hobbies, volunteerism, family life, friendships, and other activities such as home maintenance and repair add balance, challenge us, and provide occasions to develop supportive relationships with a broad variety of people.
Some people thrive on risk or constant change. Others prefer variety tempered with stability. This may vary over time or be altered abruptly following an event such as an accident, loss of a loved one, or change in the economy (or any particular job sector of the economy).
Keeping in mind that much of life is a reiterative process (live and learn), remaining resilient, open-minded, and appreciative of circumstances may be key to finding a suitable fit in a career or interim employment.
Although some families may have many connections and strong persuasive abilities to help guide career choices and manifest myriad opportunities, for many/most people, it is not a matter of taking a straight, paved road to pre-determined goals but rather creating one's own winding path by exposing ourselves to experimenting with our different skills and abilities and the opportunities which we see within reach (especially those which may be a bit of a stretch).
There are sources of information readily available to all, regardless of pedigree, such as the US Bureau of Labor Statistics, Occupational Outlook Handbook -
https://www.bls.gov/ooh/My suggestion is to embrace the freedom which currently exists to commit to a few different professions, careers, and levels of responsibility, throughout one's lifetime.
