"Roguelite" isn't really a genre, but a catchall for many types of game that use some elements that are common in roguelikes, but aren't really roguelikes.
I mean, Nova Drift and Inscryption are roguelites, but they just aren't in the same genre of game at all. One's an action Asteroids-like game, and the other a turn-based deckbuilder.
Thank´s for he further specification. I fully agree with you, although it is often treated as a genre, roguelite is in fact a wide category of games from different genres, that only share certain similarities, like having permadeath, meta progression and so on.
Rogue-lite, definition: Not a defined genre at all but just an umbrella term for games from any genre that share at least some of the following characteristics:
permadeath (a must have)
procedurally generated levels
metaprogression
short to medium length runs with victory conditions (a run can usually be finished in one sitting)
That definition of rougelike seems overly strict to me. I'd say the main difference is a system that provides progression outside of runs to make future runs easier. That would more things like FTL, enter the gungeon, and binding of Issac into the rougelike category.