Implement Lazy Drop Sort

JavaScript (ES6), 28 25 bytes

Saved 3 bytes thanks to @Shaggy

a=>a.filter(n=>~-a<(a=n))

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Husk, 4 bytes

m←ġ<

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Explanation

m←ġ<
  ġ<    Group the numbers into decreasing sequences
m←      Keep the first element of each sequence

R, 27 bytes

(l=scan())[c(T,diff(l)>=0)]

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