Is rising investment prices just profit or are we losing purchasing power?

When the price of something you've invested in goes up, does that mean you're only seeing profits or are we really losing purchasing power? Is the main aim of investing just to make more dollars from less, or should we focus on keeping the value of our assets intact? I've heard folks say they bought an item for a certain amount, kept it for, say, a decade, and then sold it for a higher amount. But is all that extra cash real profit? Not really. As time rolls on and inflation kicks in, prices for just about everything keep climbing, which we often interpret as profit. But our purchasing power is taking a hit at the same time. Take this example: ten years ago, the money a family needed monthly could buy an ounce of gold. Fast forward to today, and while the price of gold has shot up, the cost for that same family’s monthly needs has ballooned too. Now, if that family sells an ounce of gold to cover their expenses, they might pocket a few bucks. That tiny bit could be considered their profit. So, it seems off to say that anything sold for more than what it was bought for is purely profit. Therefore, profit could be calculated like this: Profit = (Sales...