The reason Logan Paul is fighting against Floyd Mayweather is because of money, and probably because of the popularity that comes with fighting against one of the greatest boxers in history. The fight is all about money; if not, someone who lost a fight with KSI in 2019 will not be planning another bout with an undefeated five-weight boxing champion.
It is on record that Floyd Mayweather has not lost any fight since he started his career. On the other hand, Logan Paul recently lost his first-ever professional boxing match in the contest with a fellow YouTuber, KSI. Logan Paul's brother, Logan Jake, also had his first professional fight with Robinson, although Logan Jake won the contest.
However, Logan Jake is also planning to take on Conor McGregor, though this fight has not been confirmed by both parties. The contest between Logan Paul and Floyd Mayweather is happening on February 20, 2021.