So for probably a year or so before the Stir/Shaken mandate came, I have been seeing a lot less phone spam. I don't know if that's typical but it was quite noticeable for me. What that tells me is that providers likely started clamping down on their shady customers well ahead of the mandate which says that regulatory fiat would have been sufficient too. But that hinges on whether my situation is typical though.
Mike
We have seen an uptick in requests for routes to Canada and the UK from Proton email accounts… We ask for business documents and never hear back.
Reading the actual FCC order, Bandwidth HAS implemented STIR/SHAKEN
everywhere EXCEPT on some legacy hardware that does not support adding the
headers.
While Bandwidth should have either replaced the hardware or updated the
software to support it by now, they did not, and they got slapped for it.
It may be that the customers connected to that hardware are being
difficult, or that, as a CLEC, they have a crap-ton of older hardware in
different physical switch locations that they couldn't or just didn't get
to upgrading or replacing.
I asked Bandwidth for details, nothing yet.
Beckman
Mine exploded since the requirement date. Some mornings I get a dozen before lunch.
Mine exploded since the requirement date. Some mornings I get a dozen before lunch.
So our anecdotes don't agree 
I know, maybe we should find out somebody who's doing research on this?
Does anybody know how this is being tracked for real?
Mike
I’ve seen an uptick, but nothing too dramatic. Maybe 4-5 junk calls a day - mostly afternoon.
What made my otherwise-largely-quiescent phone go
berserk was joining AARP.
Went from weeks between random telemarketing call to
now getting sometimes more than 100 calls before
lunchtime. Today, I couldn’t hang up on one person
offering me Medicare benefits fast enough before
another was already beeping on call waiting. 
Moral of the story?
If you retire and join AARP, put your most hated
enemy’s phone number down instead of yours. 
Matt
There is a company First Orion that does some surveys and reports on such things: https://firstorion.com/2021-scam-call-trends/
Can confirm this. ( Except it was my dad who joined AARP, and we share the same name. Apparently most telemarketer databases don’t quite deal with suffixes in names that well!)