Simplicity is the mean of excess and deficiency
There's a philosophy often attributed to Aristotle, though also theorized by Chinese and Buddhist philosophers, of the Golden Mean. It is the "desirable middle between two extremes, one of excess and the other of deficiency." This theory asserts that even good things, in excess or deficiency, can turn into something undesirable; only when found in an appropriate balance - its mean - can something remain virtuous. For example, honesty is a virtue but in excess it would manifest as tactless and rude and in deficiency, as a lie.
As with anything, simplicity can also descend into extremes. It's a practical and beautiful philosophy to live by. However, when overdone, it's entirely impractical (especially if you have a family) and in deficit, it's manifested as clutter and excess.
Some people who like taking things to extremes will question if anything except being alive and breathing is valuable and forgo all possessions. Others think the whole idea is bogus and if you have money you should spend it on whatever you want. But what I love about minimalism is that in its very definition, it's begging for balance.
Those who truly see its value as a highly practical and versatile philosophy to live by, see that it doesn't matter if you have a million dollars or a thousand dollars, it doesn't matter if you have a family or live alone, it doesn't matter if you commute to work or walk, it doesn't matter if you love to collect books or don't collect anything... it's a philosophy that customizes itself to your circumstances and puts the power of finding your Golden Mean in your hand.
What do you value? What truly brings joy to your life?
Now, what is an absolute necessity to live comfortably?
Got it? Good. Everything else is disposable. What remains, is your Golden mean. You haven't stripped your life bare of the things you want or the things you need but you aren't consumed by possessions (or responsibilities, or emails, or thoughts) either.
Adjusting your character traits and your lifestyle to account for the Golden Mean isn't a once-and-it's-done project. It's a system of checks and balances that you hold yourself to. It's a reference - a measure by which you live. We tend to swing toward extremes regularly depending upon our circumstances and only when we are mindful of those extremes and proactive about finding their mean can we begin to see its fruits.
Simplicity is the same way - it isn't a once-and-it's-done purging. It's a way of living. It encourages you to be mindful of your possessions and the value they add to your life. It encourages you to prioritize. And it empowers you to enjoy the things that you love most without distraction.