A lot of people like crypto for passive income, even though it's debatable if crypto is a good source for that. The volatility will usually be much more than your gains from staking.

However, PoS staking is a nice bonus when holding crypto anyway and offers less risk than any form of lending or providing liquidity. But let's not forget this reward must be coming from somewhere: In most cases it's a mix of fees and block rewards. Block rewards are coins created out of thin air - causing inflation if it's not compensated with burn mechanisms like in Ethereum.

If you are looking at the growth of your investment for a "scarce" currency, you would be more interested in the real interest rate. This can be approximately described as the nominal interest rate minus the inflation rate (source). In words: This is how much your share of the total supply increases over time.

To compare this I cherry-picked a few cryptos to show you how these real interest rates compare to the nominal ones which are advertised:

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All data taken from stakingrewards.com

This table makes obvious there is no general correlation between nominal interest and real interest. You really have to look into each project separately to evaluate it.

Pokadot and Cosmos have super attractive rates, but their real interest is a lot lower. Polkadot is still decent, but still just half of the 14.85 % nominal rate.

Ethereum on the other hand is the only one with a (currently) higher real interest than the nominal interest rate in this list. This is because of it's efficient burn mechanism. I left some currencies out, but ETH has the highest real interest from the top 25 coins that allow staking. Of course I have to mention the ETH burn is depending on its activity, if the activity drops ETH can also become inflationary again.

TL;DR

When staking crypto, the interest rate is only telling half the truth. Look into each projects and compare the rate with inflation. Your real interest might be much lower than you think.

Especially projects with very high rates are often very close to their inflation rates, making the real rates a lot lower.