It’s always funny looking back at stuff like this. I remember looking at old articles about Catherine Tate becoming a companion in doctor who and people were furious - and in retrospect not only was she one of the best companions, but that was probably the greatest era of the show.
Iron man was a hail mary by Marvel. Their IP was failing. RDJ was a lucky casting. Given where he was at at the time he was a pretty risky pick. Marvel didn’t really have the budget to be too picky at the time.
There’s a reason Spiderman is owned by sony and the hulk by universal.