Not completely useless if it mitigates the heat effectively and is quasi-silent.
All heat mitigation solutions cost money. But without cost specs and decibel facts, not sure how it stacks up against other cooling methods.
Watercooling is mostly a gimmick for most miners today, they do have a niche but for the most part in their intended industrial environment there's no need for watercooling. Why bother investing additional money in watercooling when aircooling works just fine for 99% of modern miners? Just additional overhead. Most of us know about the Antminer C1 and how it worked- it was the first and last factory-watercooled miner from Bitmain, and for a good reason.