90% Of Project Bounties Are Scams[
If I see a project that appeared in 2018 until now has experienced a very significant setback. Most of them are con artists.
Although the actual statistics of scams aren't recorded but the percentage is quite high than you have written. Maybe using the most popular percentage of 98% of the bounty are scam would had been more appropriate while the remaining 2% is divided between legit projects and project that'll due off due to lack of publicity resulting to them to having enough support to patronize their project either due to poor marketing or lack of proper management .