not a chance. euroleague has loads of players who would be solid benchplayers for nba teams and have been in the past. the top-tier players would easily start for most lottery teams.
besides that, dominating grown men at 17 in a league that's second best in the world (spanish league) is very impressive. the physical aspect is a massive part, college ball nearly always need a lot of time to adapt to playing against grown men, meanwhile doncic has been doing it for years before getting drafted.