Oh Jesus what are you talking about. Xmen had great supporting characters but An unknown Hugh Jackman was the lead. Iron man had a stellar cast but let's looks at other films. Cap had Tommy Lee Jones , Stanley Tucci and Hugo Heaving. Chris Evans also while not as elevated as he is now was still as well known as a couple actors you listed. Thor had Natalie Portman, Skarsgard,Anthony Hopkins, and Rene Russo. GoTG had Zoe Saldana, Bradley Cooper, Glen Close, Michale Rooker, Josh Brolin,Benicio Del Toro,John C Reilly,Vin Diesel and Lee Pace. Black Panther had Chadwick,Michale B Jordan,Angela Basset,Forrest Whittaker, Lupito,Sterlin K Brown,Martin Freeman, Daniel Kaluuya and Andy Serkis. Any MCU movie with a lesser known Star has a great supporting cast. Your just making stuff up at this point.