Your numbers are not right.
I don't know which dictionary Wordle uses, but for scrabble competition (SOWPODS) there are 12478 valid 5 letter words. [1] By my experience the Wordle dictionary is similarly complete.
But while you overestimate the dictionary size you underestimate the number of moves required. I don't play optimally but have done 150+ rounds keeping all constraints satisfied with each play. The modal number of moves to win is 4 (about 50% of games); I get about 20% in 3 moves, 20% in 5 moves.
Over 75% of the time I find 4 or more constraint satisfying moves, even trying to favor eliminating common letters. It is implausible that an optimal strategy would decrease this to 3 moves.
Also to keep in mind: Wordle's dictionary of possible solutions is much smaller than the dictionary of allowable guesses. I have never seen an unfamiliar word as a solution, though I am far from knowing all 5 letter dictionary words.
[1] http://scrabbleguru-sowpods.blogspot.com/2013/01/words-by-le...