Dedicated GPUs are obviously going to be more powerful. I've never run ai before so maybe someone else can weigh in on the requirements for it, but I can say for sure that an igpu is good enough for jellyfin transcoding. It also depends on your budget, do you want to spend the extra money just for a dedicated GPU?
If you go igpu route I think that Intel is recommended over AMD, but you should probably do extra research on that before buying
I don't know anything about this beyond what's written in the post, but it sounds like if a podcast episode on YouTube has been properly sporsorblocked, then it should skip ad reads as well (keep in mind that sponsorblock is crowd-sourced, it doesn't automatically work it's magic)