https://wccftech.com/ios-15-features-stronger-wpa3-security-when-using-personal-hotspot-tethering/

If you are going to use your iPhone and iPad as a personal hotspot for internet, then you will be pleased to learn that security will be handled by WPA3.

For quite some time now, iPhones and iPads have been able to connect to WPA, WPA2 and WPA3 protected Wi-Fi networks. But when it comes to the Personal Hotspot feature, security has been limited to just WPA2. While many of you might not care about it that much, but it does put you at risk if you are out in the public as someone can brute force their way onto your network, putting your private information at risk.