Allowed to say salaam while in prayer, yet not during khutbah? Does anyone else find this odd?

Assalaam-u-alaykum, I was watching a YouTube video (watch from 5:49 to 6:17) by Muslim Lantern: https://www.youtube.com/watch?v=zt5aWPQGa0A&start=348&end=377 During prayer, it's apparently a sunnah to return salaam to a fellow Muslim if acknowledging their salaam by signaling with the palm of your hand. This is referenced is Sunan Abu Dawood, Book 2, Hadith Number 0927; Narrated Abdullah ibn Umar: https://sunnah.com/abudawud:927 My question is if the salaam is given such importance during a prayer (when you should have most concentration and are speaking directly with your creator), why is returning the salaam of a fellow Muslim not allowed during Friday khutbah when everyone is listening to the surmon by a khateeb, which is also obligatory to the jhummah prayer? https://www.youtube.com/watch?v=JNtXldFs1yQ https://islamqa.info/en/answers/45651/is-talking-during-khutbah-permissible I'm a little perplexed by this upon discovering this dichotomy. Does anyone know why there are differences here? May Allah guide us all and only He knows best. Jazakallah Khairan.