Your article is a bit misleading with the mixing of denominations.
This article says they got about 50 tons in a month, so ~600 tons a year.
There’s ~100-200 million tons of plastic in the ocean now, with a further 14 million tons being added every year (33 billion pounds in metric tons).
14 million tons at 600 removed a year for 1 boat is 23k years. But at 23k boats that’s 1 year. There are about 6k shipping monstrosities out on the oceans at any given time, 50k ships navigate the oceans every year.
If we increase the yield of these boats by just 2 fold, these numbers start making sense to fix within a lifetime, which is amazing. Without counting the reduction in waste added we can easily fix.
Humanity should have expected the cleanup to take as many generations if not more than it took to put plastic in, we’re lucky we can get this close.