Yes, he's definitely beatable this edition of the Olympics but Michael Phelps just keeps on adding glory and rewriting record books in this quadrennial event. Entered in 7 events this Olympics (Men's 100m Butterfly, Men's 200m Butterfly, Men's 200m Individual Medley, Men's 400m Individual Medley, Men's 4x100m Freestyle Relay, Men's 4x200m Freestyle Relay and Men's 4x100m Medley Relay), Phelps has already swam 5 events up to this moment and has collected 2 golds for 200 IM and as part of the relay team (4x200 freestyle) and 2 silvers for 200 m Butterfly and part of the 4x100 freestyle team. Those feats came after his disappointing 4th place finish in the 400m Individual Medley.
In the process of claiming those medals, he has again rewritten record books. He is now the most decorated modern Olympian with 20 medals (16 golds, 2 silvers and 2 bronzes). That comes with his record as the most number with gold medals as well. He has 2 events left for him to take and if he wins any of those, he'll just put the bar higher for other swimmers to beat in the future.