Kaspersky Safe Kids is good. I'm trying KSK, and it works well. Apart from categories, age-appropriate blocking, it heuristically (or Artificial Intelligence) blocks on Search Engines and YouTube. It supports search results on Bing, Google, Mail.ru, Yahoo, and Yandex. The changes applied on the web control panel are instant. Monitoring, blocking, reporting work well and don't affect the net speed. And locks SafeSearch on Google but not on Bing. I did not try other search engines. The web control panel is sometimes slow. I have provided feedback to Kaspersky to add options to enforce SafeSearch on Search Engines and lock YouTube Restricted Mode. And improve the web control panel. Along with KSK, I have added Search Engines and YouTube addresses in the hosts file to enforce SafeSearch on Search Engines and lock YouTube Restricted Mode. With this method, SafeSearch on Google, Bing, and YouTube Restricted Mode cannot be disabled. And the restrictions cannot be bypassed by cleaning browsers, logging in, and using a VPN. And added Cloudflare Malware and Adult DNS Servers on Network Adapters. I'm using the mentioned Parental Control setup for kids between 9-12 years old.
