It stops too soon. Once it's in a gulf or ocean, where do those currents take it?
And the clouds are in fact made of solid crystals of ice, which then melt to make rain.
It's all a cycle, with many sizes of feedback loop. By loving our neighbour the ocean and picking up litter on the street, we can change it. The butterfly effect means that even a little helps.
https://ourworldindata.org/plastic-pollution
As a (possibly misheard) lyric, about clouds in the sea:
Rhythm you have it or you don't
That's a fallacy, I'm in them
Every spiralling tree, every child of peace
Every cloud in the sea you see with your eyes
Gorillaz - Clint Eastwood
https://youtu.be/1V_xRb0x9aw?list=PLfNF8TQij08oma_987vYrzswd...