These inventors are usually from very poor countries trying to replicate a known vehicle. I strongly believe most of them are doing it to get some sort of recognition or to get funded to achieve financial freedom (or to find a job?).

Tuk Tuk didn't show anything extra other than having solar panels on the sides. Simply, slapping several panels to a solar charger for lithium battery pack to operate an ebike-ish drive is not an invention in my opinion.