For steady inflation that's not already priced into rates/prices/etc, the solution is pretty simple. Borrow a lot of money at low, fixed rates. Invest in hard assets like real estate. To the extent that you invest in equities, invest in businesses with a lot of pricing power and little competition. Their profits will tend to go up more than the rate of inflation, and then stock prices tend to track profits.

Problem is that inflation is rarely steady. Typically you get stops and starts. Inflation will rise, and the Fed will try to contain it by raising rates. Then the raised rates create a recession, all asset prices fall, the Fed flinches and drops rates. Inflation takes off again. Repeat for a decade or more.

In an environment like this, you can't lever up too heavily, and you need to actively manage. Otherwise you'll get reamed by the busts. Optimal strategy is to buy surviving high-growth stocks right as the recession gets to its peak, as everyone feels like everything's going bankrupt, and then hold them as rates drop and the economy recovers. Then sell right as the Fed signals it's going to get tough on inflation again.

Optimal strategy is pretty hard to execute. Failing that, it's often best just to buy & hold profitable, low-competition businesses.

The demographic time-bomb of everybody retiring at once and trying to cash out of the market at the same time is another issue. There's no real fix for this: living standards are going to have to drop, for retirees or workers or both (and more likely retirees). The way to profit from it is to look for companies that are successfully automating parts of elder care, and then invest hard in them.