the most dominant for his time maybe. i know bobby fischer worshipped him and said that given modern chess theory he’d have beaten anyone.
the scale in that vid expands though, guys like carlsen and kasparov peaked much higher in rating than morphy, but elo rating scales do inflate over time so it gets complicated comparing across generations tbh. especially given everyone builds on the theory and innovations of the previous generations, not to mention the rapidly improving quality of chess computers etc. nobody from the 1800s is gonna beat even the 1000th best player today, but that doesnt mean they weren’t more naturally gifted, they just had way more primitive theory to study.