You seem to be confusing price increases associated with supply and demand with inflation, which is a reduction in the value of the currency per denomination. Both of these things can affect price but they are very different.
Price changes related to supply and demand are specific to the products or services where supply and demand fluctuate.
Inflation, is related to the currency and has an impact on the entirety of products, services, and assets simultaneously.
Inflation is not specific to capitalism. In fact Russia is seeing tremendous inflation atm.