I know quite a few ways to make passive income from crypto, dividends from exchanges are a great one, for example, KCS kucoin and VX vitex, both share exchange profits to holders of their token, NEX nash also but I hear their returns are terrible.
staking is a great way to also make a passive income many coins out there produce new coins and you can stake your coins to get a bit of the new coins produced, some coins that have staking: ETH, ADA, VITE, NEO, TEZOS, WAVES, ICON, MKR, IOTEX … there are many many more.

the only problem with staking is that you are dilution the coin supply, so in a way, you are not really gaining. because yes you are getting more coins but so is everyone else and the total supply is going up as well.
the one I love in the list above is VITE because they burn vite tokens on their exchange VITEX which compensates for the new coins created on the vite blockchain to the point where it is now deflationary. So yes you heard that right while you get vite coins by staking the network has fewer vite coins because of that burning of vite fees on vite trading pairs on vitex.

An amazing balancing effect and what could be a very powerful passive income source in the future.

the zero transaction fee coins I know are:

Nano
Vite
Iota
EOS

the incentive on all 3 is the minting of new coins to pay for the network inflating the coin supply, except Vite, they burn vite fees from their exchange vitex making vite deflationary at the moment as more coins are burnt that are minted, which is very interestingbesides the above there are also cryptos that have low fees like:

XLM fee 0.00001 xlm
TRON
XRP