I don't think lending and bot trading is a good way of earning passive income. It might be an efficient way of earning passive income but it's not guaranteed to give out profitable results every time. It is quite risky too.
I don't know about open trade and vertex.
I kinda like staking and used to stake some coins earlier but then the profitability decreased over time and hence I left staking.
I don't find any coins which are profitable for staking but you guys do let me know if you know coins which are worth staking.
That's true, it definitely requires being a little bit active, setting and adjusting strategies. But with certain platforms they don't guarantee you massive profits, but quite constant most times