is there any website available to track past succesful bounties since 2018? please drop a few list if you have any
So far there has been nothing like that. Most only provide bounties or ICO / IEO lists that will or are currently in progress. Even if there may be only limited articles or threads in several forums and blogs, and even then with an objective perspective. Well, by 2018, the most successful in my opinion is Harmony.
For ieo there has actually been success, but when it comes to bounties, the level of payment currently available is not so great. so it's the same. Moreover, this year there were not many successful projects