In reality I did not read anywhere that they intend to create a profile on you. What I read is some fuzzy idea about a future in which AIs could be customised to the individual level. So far, Kagi's attitude has been to offer features to do such customisations, rather than doing them on behalf of users, so I don't see why you are reading that and jumping to the conclusion that they want to build a profile on you, rather than giving you the tools to create that profile.
It's still "data" given to them, but it's a voluntary action which is much different from data collection in the negative sense we all mean it.