you clearly don't listen to him enough to prove any of those points, so I'll just disprove them for you
1. no bars - Slime Season 3 is full of good bars, "With Them", "Memo" and "Worth It" are just some lyrically complex song filled with references and clever wordplay. He matures more and more lyrically with every album, granted his previous stuff was just basic run-of-the-mill trap but just listen to So Much Fun.
2. no double meanings - "I'm on the outskirts chasing after green smoking orange kush feeling like a cantaloupe" from Blanguage, "she sucking dick on a plane and i call her airhead" from "With Them", "I'm smoking loud yall ni**as smoking libraries", that's just some examples of his use of double entendre (i guess that's what you mean by "double meanings" but you clearly don't know enough about rap to know about it since you're out here dissing Thugger)
3. no sick metrics or flows - have you ever heard his collabs with Metro Boomin? The Blanguage and Hercules perfectly showcase how Young Thug can ride a beat effortlessly and make it sound great. His flows are crazy and unpredictable, but that just makes his music more unique.
4. nothing inventive or new about him - you are aware that half of the rap game nowadays looks, dresses, and behaves the way Thug did way back? Him, Future and Lil Uzi pretty much paved the way for the "Lil" rappers with the colorful dreads, androgynous fashion and jewelry and just expressing oneself without care for others' opinions. He is one of the most influential rappers of this decade and I'm still shocked that people don't admit it.