What should the rate of returns suppose to be by right on a usual basis whenever we talk about getting back high returns for our investment? (Do state the percentage)

Many people measure it against the S&P 500 rate every year

Indeed it is subjective. Not everyone has equal access to the same opportunities and share the same investment risk and financial situation. So in generalization, a 10% is good.

If you know of an easy way to get 'High returns' please do share, then you can see if people think its easy, risky or indeed high returns.

Average 10% over the long term is possible. and that will allow you to double your portfolio every 7 years without new money.

There is no limit to high returns, everyone wants high returns but do note most high returns there is risk so pls do your own due diligence.