I would personally value lautaro more than griezman, it's kinda similar to our arthur-pjanic trade.
Because of age? Griezmann doesnt have several years of underperforming, he was flatout great for Atletico nonstop, and he is bought by a club that dont wanna play him in his position. If he goes to ANY other top club, he will perform as superstar level all around attacker he was with atletico.
Age difference matters to a point, quality on pitch Lautaro is nowhere near it yet. He scored 12 goals and decent half season, and suddenly he is rated as 110m player. Needs to show way more imo.