I'm a big proponent of paying for things instead of using ad-supported things, so I don't mind paying for Kagi -- but I also have subscriptions and other monthly payments that make me think hard before signing up for a new one. $10 a month for Kagi, $10 for a webcomic Patreon, $5 for a musician's Patreon, $10 a month to support Mastodon.social, $10 a month to Internet Archive, and an assortment of other monthly (or yearly) subs/payments... plus streaming, plus ... it adds up.
Ideally if more people were supporting these things the monthly charges could be less -- e.g., if Kagi had more users their monthly could be $5 instead -- but pricing and getting people to pony up is hard.