Jay came out at a time that genre changing classics were being dropped regularly by hip-hop GOATs. He's made music with and/or had his music and his brand go up against Biggie, Nas, Pac, DMX, Wu Tang, Big L, Big Pun, Scarface, Redman, The LOX, Outkast, Eminem, Snoop, Dre, Kane, Rakim, Camron, 50, Kanye, and so many more during the peak of the genre and at a time when great music was being released weekly by great artists. He was involved in what is most likely the biggest and best rap beef in the history of the genre against another one of the GOATs. He made music with and brought out Michael Jackson at Summer Jam. He has the 2nd most #1 albums ever behind only The Beatles. He made it so an artist like Drake could even come along and be first and foremost a pop artist that makes rap music.
With all that said, there is literally nothing Drake could do to ever challenge Jay as the most important and impactful artist in rap history. Jay was the biggest rapper in the world when the genre was at it's peak, everyone was consistent at that time, which made it so much harder to stand out and make a lasting impact. Drake realistically has only 2 competitors in Kendrick and Cole and they don't even legitimately compete with each other. In the late 90s/early-mid 2000s it was kill or be killed, it's nothing like that now. There's like 1 artist for each lane in rap and they completely steer clear of each other.
Rap was corporate owned during Jay's prime, but the culture was still apart of and dictated by the streets, you couldn't be a pretender at that time or at least had to do everything you could to hide it. Now it's corporate owned and it's obvious. Drake is closer to Adele than he is to artists like DMX or The LOX, artists that Jay made classics with, beefed with, and outlasted both commercially and in terms of making great music. A street dude in Meek got clowned incessantly by internet nerds and big corporations in a beef with Drake, a forgettable beef at that with mediocre music that no one will remember that actually took a backseat to memes on IG and Twitter. Drake's made some great music, and he's been extremely successful commercially there's no denying that, but he's nowhere near Jay in terms of legacy and never will be.