The relationship between risk and returns

I was thinking about how higher risks are almost always related to higher returns. Most people if not all take it as a matter of fact. But my thoughts are that it is not, that when for example it concerns investment, investments involving higher risks usually have higher interest rates (returns) not because it is matter-of-fact universal law, but because people's behavior.

Higher interest rates are always attributed to investments where there are fewer buyers. If an investment is heavily bought or demanded, its interest rate would experience downward pressure to settle at a lower rate. Think about prices.

So the only reason why returns for riskier investments are higher would be because most people are risk averse - they don't want to take riskier portfolios. This naturally causes interest rates for higher risk investments to be higher than average.

But what if people, for whatever reasons, love risk? Then higher risk investments would have lower returns compared to lower risk investments and it therefore would have been "lower risks are almost always related to higher returns".