Crypto staking: how much do I actually earn?

How much are you willing to lose if the platform fails or if there are technical issues?

Because the real answer is that the nominal yield you see (like 3-4% per year) isn't what you actually take home. On Lido for example you'll see an APR listed, but Lido takes a commission from your earnings (I don't remember the exact percentage, but it's a significant cut), and then the platform where you stake could have additional fees. Same thing on Kraken and other exchanges: they tell you how much you earn gross, then they deduct commissions that vary from platform to platform. The net yield you actually receive is always lower than what's advertised initially.

Then there are the underestimated risks: staking doesn't equal guaranteed money. If you stake on a centralized platform and it runs into problems (like what happened with various exchanges), your ETH could run into trouble. And there's always the risk of slash penalties, though on Ethereum mainnet it's basically nonexistent if everything works properly. In practice, the real earnings after commissions and taxes (if we report them, which we should) is way less attractive than what it looks like on the homepage.

Read the ToS and fees for each platform carefully, compare the numbers side by side, and factor in that you won't earn what they promise. If you're not willing to risk a portion of your ETH, don't do it.