Kagi is fairly recent, something like a year old, so having 15 years in tech won't help you here. I doubt they're astroturfing like you're claiming, they actually have a decent number of users and a good following on HN. You can look at the numbers their previous posts on HN did[0].

Disclaimer: I'm also a happy user.

[0]: https://hn.algolia.com/?q=kagi