It's just really hard to affirm that something has "no practical use whatsoever". Maybe it doesn't have use "now", maybe it doesn't have "direct" use but can be used for another finding that is useful, Math has a long story of finding out stuff that turns useful later on.
True. Though ~99% is still useless in the end.
We are not at the end, how could you possibly be confident in this claim?
As they say: 80% of marketing is useless, you just don't know in advance which 80%. Same with math