Yeah Griezmann is only Atletico Madrid's all-time highest goalscorer and one of La Liga's best foreign imports ever. Also scored 40+ goals for France and gotta be one of their top 3 assist providers in history...playing a lot of his 130+ caps as a MF. How many times did he single-handedly save Simeone & Deschamps' asses. The guy's won the WC, Europa League, Liga, Copa del Rey...reached the CL final, WC & Euros runner-up, was in the running for the Ballon d'Or multiple times. But yeah he ain't special.
If you get excited by a pace merchant running in a straight line, go watch track & field. Ask any Rennes, Dortmund, Barca or PSG fan who knows their footy and they'll you what Dembele is worth...and how fast they'd bite your hand off for a swap with Griezmann.
You're obviously entitled to your opinions, but calling Griezmann nothing special and raving about Dembele, you gotta be on some serious sauce, pal.