So why are taxpayers funding this again?

The Herald reports:

Half the boats challenging for the America’s Cup will not make it to the start line in Auckland in 2021, according to a report.
Newshub have reported that all three teams that filed late entries have failed to get enough money together to stage a challenge.
“It is not surprising that some of the challenges aren’t going to make it to the start line,” America’s Cup veteran skipper Chris Dickson told Newshub.
“It’s an expensive game, the America’s Cup.”

It leaves Emirates Team New Zealand facing the prospect of losing millions of dollars.
Newshub reported that Malta’s entry is “dead in the water”, DutchSail is resorting to crowdfunding and California’s Stars and Stripes is currently drafting a media release announcing its withdrawal.
That would leave Luna Rosa, the challenger of record, INEOS Team UK, backed by Sir Ben Ainslie, and American Magic, from the New York Yacht Club.

Just three challengers. That must reduce greatly the claimed economic benefits of hosting. They’re saying the challengers haven’t officially withdrawn yet but neither have they paid the entry fee that was due.