What makes a song qualify as rap?

I used to be able to easily tell the difference between Rap and other genre's, and for Rap I would think of songs like Humble by Kendrick Lamar, Doja by Central Cee, The Box by Roddy Rich, WHATS POPPIN by Jack Harlow, etc. These days, Rap songs don't really sound like Rap to me.

For example: A lot of drake's songs and some of Travis Scott's songs (Nightcrawler, etc) just sound like pop to me. Tyler the Creator's Chromakopia album is considered Rap by everyone but it sounds like a whole new genre to me. Some of Playboi Carti's songs sound like metal to me.

And some songs that do sound like Rap to me like Timeless and Heartless by The Weeknd are classified as R&B.