Sorry about the discouraging job search.
The low pay for PPC surprises me. That strikes me as an area where someone with knowledge has immediate positive ROI and the difference between good and bad is large.
The low pay for SEO doesn't. It is very hard to move the needle quickly and cheaply now, barring deep technical issues, and that is what SEOs promised for so long (and delivered into the early 2010s maybe). What I see is SEO firms that do perfunctory keyword research, suggest some change to an H1 here or adding some phrase in the text here. Often the phrases they suggest adding make no sense. And for this they charge a buttload of money.
It reminds me of something a street musician said once. His riff went something like this: "Someone came up to me the other day and said, 'You're pretty good.' I said, 'If I were great, would you be able to tell? Most people can't, but there's a difference and, actually, I'm great.'"
It was a schtick, but it was true - I've seen big Vegas magic shows that didn't wow me like this guy. He was great.
Anyway, I suspect a lot of the issue is that most of the people offering low wages don't know the difference between someone who hardly knows anything and someone who is great, so they don't see why they should pay for great (and fees are typically more an indicator of agency size than agency skill, so they've absorbed that lesson too).
