The UN has historically allowed quite a few leaders to speak that have been responsible for all sorts of human rights violations. Gaddafi was allotted 15 minutes but spoke for 96. No mass walkouts. Castro spoke for 269 minutes. No mass walkouts. Putin spoke many times with no mass walkouts.
Netanyahu:
2024: substantial diplomatic walkout
2025: delegates from more than 50 countries reportedly walked out
2026: dozens again left as Netanyahu began speaking