The acid content of your wine, beer, or sugar wash is an important factor for a number of reasons.
Acids in wine making are important because the level of acid present can create unique flavours, or balance the flavours, in the wine between sugars and tannins. If wine is too low in acidity it may feel “flat” and not age well. However, if the acidity is too high then there may be off flavours that have to be reduced with wine chalk (calcium carbonate). Acidity is also important in high-alcohol wines because it is needed for fermentation - if your must is too low in acid (too basic) it will not be able to complete its fermentation. It is important when using fresh fruit recipes to follow any instructions about adding acid or wine chalk.
Acids in beer making are important for changing the character of the water you are using. “Wine Chalk” or calcium carbonate, can be used to lower the ph level of your water.
Acids in the creation of high alcohol sugar washes are important because they are needed for fermentation to occur. If using simple sugar water with specialized Lightning Turbo Yeast an acid treatment shouldn't be unnecessary to achieve 23% ABV. However, if you are using a different yeast or different base ingredients it may be necessary to treat your wash with acid so that the yeast can continue to ferment to your desired ABV.