Ask HN: What full-time self-project should I do in 2018?

[Throw-away for obvious reasons; on HN since 2012; 25 years old] I'm one of you who hangs out on HN/PH/Reddit. I joined CS in 2011, then dropped out to start freelancing (because I couldn't pay college fees) in 2013. After three years, in late 2016 I quit freelancing, and since then I've been building utility apps and simple mobile games for the last two years. Some of my apps are bringing me Ad revenue; combined revenue from my projects might sustain me for a couple of years.

By working in dozens of small-scale projects, I have gained a diverse range of skills; I'm pretty good at Unity3D, image manipulation using C++, native mobile apps, system/server administration (setting up web/mail/database servers and containers). Since I have had a passive revenue stream, I find myself spending a lot less time working; I just spend most of my time reading articles on Medium/HN/PH and tinkering with new technology, without any motive of commitment with any of those (take blockchain and flutter as two examples).

My apps might support me for 9-12 months without actively maintaining them. Personally I'd like to involve myself in a project that doesn't only involve writing CRUD and APIs. I'm pretty burnt out of all these stuff. I feel I'm doing the mindless programming even if I'm solving interesting problems in a while. I think I'm not working on something important enough, and will soon lose my passion for development. To fix this I have thought of three options-

i. help the open source community, because without it I'd probably be selling peanuts in the railway station,

ii. start working on to hardware/IOT with a lot of learning (Logic, Computer architecture, signals, boards, basic electrical, etc.)

iii. work on a technology that is promising, as well as interesting enough for coming years, like ML/AI/DL

I'm not a native speaker of english, and belong to the 3rd world country in South-East Asia, please pardon my ignorance of language. What would you suggest?