I really like that comparison and can completely understand that drive - unfortunately it still doesnt work for me, because adventuring in DnD means being a heavily armed combatant. Its not like like D&D adventurers just want to broaden their horizon - they are ready to slaughter everybody who stands in their way and are very proficient in combat. I think your suggestion would better work for less combat more narrative focused games, but in D&D 90% of character progression is based around combat. And that doesnt fit the happy family live for me, at least not in a campaign with "serious" storytelling.
I don't believe happy people with a stable support network leave everything to go heavily armed and ready to kill in some dangerous environments full of enemies. I never had an adventure where we "just" risk our own lives - the lives of a lot of other creatures are always in our hands too and characters get blood on their hands pretty quickly.
If its just a beer and pretzels game where we don't care about realistic character motivations, sure absolutely. I've played such characters myself. But they always are a bit "cartoonish" to me.
I'd like to introduce you to the (claimed) life story of one Quintus Horatius Flaccus, aka Horace, one of the great poets of ancient Rome.
He came from a good family. His father was a freedman, a
colonus, someone who had a farm that produced enough money to give the family a comfortable life, and apparently may have worked as an auctioneer's assistant, ensuring the family had plenty of money. His father spent
lavishly on his son's education, up to and including temporarily moving the two of them to Rome to ensure his son got the best education possible. By all rights, Horace had a devoted family, where he was loved and cared for, and had all the comforts money could buy, up to and including getting to choose when to live in Rome and went to live in southern Italy (the region Augustus named "Lucania et Bruttium", in the village of Venusia).
And yet! Despite all those creature comforts, despite the lavish life he lived, despite his father spending fantastic sums on Horace's education, Horace chose to join Marcus Junius Brutus--yes,
that Brutus--as a soldier fighting for the republican faction, as opposed to (what we would call) the "imperial" faction led by Octavian and Mark Antony. Being a well-educated Roman, despite not coming from a high-status family, he was installed at a moderately high-level officer rank, learned the ways of war on the march...and then he claimed to have deserted the field, leaving his shield behind, at the first major battle.
Still, the point stands, that Horace lived a life of adventure for a time, despite coming from, if not the lap of luxury, then at least a happy, supportive home life. He wasn't even the only major author of antiquity to do exactly this! The Greek general/philosopher/historian Xenophon made his name, in part, by being one of the generals who led the "Ten Thousand" Greek soldiers who had assisted Cyrus the Younger's (failed) attempt to usurp the Achaemenid throne from his brother--and writing the
Anabasis about it afterward. Well-educated, presumably well-supported young Greek of high status...who still hared off for not just a dangerous
and very specifically armed-combat job, but one that almost ended in utter disaster for the soldiers who participated.
Some people really, genuinely are just
that adventurous, and feel the call even when they know from the very beginning that they are committing to killing other human beings. (Indeed, being squeamish about killing other beings you know to be human just like you is...kind of a modern-era thing?)
