You can be a professional (by definition being paid) athlete and still never be in the top 10% of players (see decades of PGA [golf], ATP [tennis] results etc). I’m not sure on the definition, but there’s absolutely tiers of professional players. Take the NBA (basketball) - there’s over 500 players in the competition, they’re good by definition but there’s a subset that are elite. There’s further subsets, for example “generational” which are “once in a generation talent” etc.
However, being an Olympian doesn’t make you elite by default (in fact there’s numerous “loop hole” athletes that prove this is the case, eg Elizabeth Swaney).