Binance I think it also offers it, but with binance you earn for sure the cryptocurrencies or you just enter a draw for answering the questions correctly?
Former but it depends if you are eligible
The Binance “Learn and Earn” rewards are for targeted Binance users only. New users need to complete Identity Verification first before they can earn “Learn & Earn” rewards. Please note that only specific Binance users are eligible to receive rewards for certain campaigns.
and if there are still rewards left
How many learn and earn rewards can I get per day,because I only did one Course and on all my courses it says "all rewards reedemed,stay tuned!" Is it supposed to be like that or...?
And in the other platforms? can you win cryptocurrencies? or just answering correctly gives you the option to enter a draw?
There is no one size fits all but for sure there would be a catch such as completing KYC. Start with reading each promos' ToS.