A great way to avoid not getting paid for your work is to deal with a reliable bounty manager and even better, work on coins already listed on a high quality exchange. I have been using KuCoinPlay and it has both those attributes. I have averaged $200 in earnings each month.
the current situation is very difficult for us to know that the project is scam or not in the future because every campaign project launched will always have many participants from rank legend until Jr.member. and this is caused by many bitcointalk users now. thus making it difficult for us to know good projects in the future. but I have my own way of finding projects that continue to pay participants and not scam projects. so until now I continue to receive payments and projects that I follow always succeed in getting into the market exchange, although sometimes the price is disappointing