I am on T-Mobile. There was a point when most of the spam to my phone was from Scam Likely. Then the robocallers learned that this is the truth, and I get spam about my credit card and something in Chinese that isn't so flagged.
I haven't gotten a single spam call since enabling the blocking.
Verizon Wireless offers it for $2.99 a line: https://www.verizonwireless.com/support/call-filter-faqs/
Not sure about the other major carriers.