Hey there Scruffy!
That's good advice no matter what the footwear strategy is.
I know we're drifting off topic here, but you also bring up a good point around the question of support. Assuming that the most important support is the human body itself (we are made for walking), then we need to strengthen our feet, ankles and legs, improve balance, and have good stretching for all our various tendons and ligaments. Personally, I use Tai Chi and Pilates to get in shape for each summer's backpacking. Also, I find using thin, flat water shoes (Five Fingers also do the same thing) around the house and yard all spring to help strengthen calves and feet because they force a slightly different walking mechanic the really helps with supporting muscles.
Then, the question of footwear is whether it cooperates with the natural walking mechanics, or whether it compensates, or whether it inhibits. I look specifically for shoes that fit my foot (not just any NB will do) and that provide good support (my feet need good arch support and heel alignment). While my shoes have always been sufficient for me, I know many people replace their shoe insert with Superfeet inserts to give them the specific additional support they need. I've found that a quality running store is 10X better than the best outdoor store for getting a suitable trail walking/running shoe, precisely because they people are skilled specifically with feet and body mechanics.
Good balance and conditioning with a 1 pound shoe that cooperates with body mechanics are far better at preventing slips and falls than a heavy, 3 pound boot-encased foot with constricted ankle movement (and therefore constricted flexibility) that compensates for poor mechanics and inhibits good mechanics. Moreover, legs are less tired and therefore less prone to late-day falls, and can comfortably (relative term here) sustain greater mileage.
As to longevity, I find it interesting that most of the people who repeat "thru-hikes" of the Appalachian Trail (3,500 KM), or the Continental Divide Trail (5,000 KM), or the Pacific Crest Trail (4,300 KM) do so in sandals and trail running shoes (NB, Brooks, Salomon, etc.). Many people do this right up into their 60s and 70s, and even into their 80s. In fact the conventional wisdom on these trails is to use shoes, NOT boots, and that wisdom is driven by those who have hiked those trails over literally dozens of years.
Yes, it is contrarian, but I've never met anyone who, having seriously made the move from boots to shoes would ever go back.