The most dangerous thing to say is, "That is the way we've always done it."It's the quintessentially modern approach (and by modern I mean the past 200 years or so, it's a short time in human history). Always we should be blazing trails, innovating, rejecting the old and outmoded ideas of five months ago.
Our pace of technological innovation and information generation mandates it. We must be ever adapting and embracing change. Enough of life is in flux automatically that flux itself is considered a necessary or desirable state.
"Way" is a beautiful word, though, with far more meaning than we usually notice in it. It is a path, a road. Something that is both the sequence of steps between here and there and an entity in itself. "The way we have always done things" isn't just an arbitrary list of procedures; it is a path that has been tested and refined through the experience of much time and many people. To preserve it inviolate is not the nature of a way; a way adapts over time to changing circumstance. But to always be ignoring it and starting over is to waste a great deal of information that has had the opportunity to coalesce into wisdom.
What we have instead of ways is random data points. I saw an article recently, one of hundreds like it, about "9 Things Insanely Healthy People Do In the Morning." Individually, most of the things were reasonably likely to have been proven to be healthy in one regard or another--like drinking water, or exercising. Collectively, no mortal under the constraints of the space-time continuum could have accomplished them all, even if they lacked such common accessories as children and a job. It was most certainly not based on the actual practices of healthy people, but on this study over here and that study over there.
It is the nature of current scientific inquiry to be primarily concerned with isolating one factor and trying to find its causes and effects. Which is well enough as far as it goes. But at a human scale, factors do not live in isolation. This thing we are doing here influences four things in sixteen different ways which then influence each other in other ways. One small change that fixes one small problem may set off dozens of larger problems. A six-month study looking at three things has only the smallest of insight on how to actually live. Which is why in another six month another study will come out saying the exact opposite and there will just be more fodder for the wars of We Have Everything Figured Out This Time.
It takes the actual experience of many lives to find ways of living, and they will never be reducible to individual factors. They will be ways, the way we have always done things, and if you try to poke at the individual parts they will always be full of flaws or opportunities for theoretical improvement.
Speculative fiction tends to split on whether our technological innovations will usher in apocalypse or paradise, with apocalypse the more popular outcome. Odds are against extremes, but if we are to have progress and not just change, it will be because we have found ways of being through lifetimes of experience, because we are willing to pay attention to the whole picture not just the data points, because before we throw out the old ways as relics of an unenlightened past we are willing to pause and find out why they were where they were.