I had to figure out the pH angle to make some beers come out great....nailing down a specific water profile isn't necessary.
At the beginning level, that is what we need to get across. Improper wort pH will confound anyone, but its the element that everyone...including beginners have to address to have a decent chance at creating beers that they can admire. In most cases, tap water has too much alkalinity and your wort and beer pH will be higher than desirable. Dull, flabby, and even icky beer is often the result.
The mineral profile is much less a concern...unless the water crunches when you drink it.
If you are lucky enough to have a water source that is nearly mineral free, you have a decent chance of success. A lack of minerals is unlikely to ruin a beer. But we all need to pay attention to pH. All brewing requires acid in some form.