I bought bitcoin when it was trading below $1000 and I am still holding it and I spend zero efforts after buying and keeping in cold storage. That cannot be called as passive income generation with respect to current price of BTC?
Honestly people are looking for peanuts by leaving off gold mines when they are hunting for passive income generation. Bitcoin must be a very good opportunity for generating passive income with comparatively zero risk. But probably people are looking for multiplying their bitcoins rather than gaining value in USD. Because, if you're going to risk in something with your 0.05BTC then if you may gain some 0.01BTC then you will end up in 0.06BTC but if you buy bitcoins for $100 (some 0.03BTC) and after 4 years of holding then your $100 worth of bitcoin will become $1000 but you might be holding same amount (0.03BTC) of bitcoin.
But, I am into bitcoin holding for generating passive income as I will not bother about that I am gaining in BTC or in USD. I am just looking for making my networth to be growing over the years.