I feel like Niantic only handles high-profile spoofing incidents
In the last couple of years I and others have had excellent luck getting high-profile spoof accounts banned very quickly, and the vanguards have helped get portals restored. The cases I've dealt with have involved high-value durable portals, such as those that require a difficult mountain hike to a very remote location.
This week I observed an account leveling up in my city that appeared to be either spoofing or someone's alt based on play patterns-- L5 accounts don't build a portal with VRMH/VRHS, glyph it for lots of keys, then expertly microfield an area at 2-3 a.m. I mentally filed it as suspicious and decided to keep an eye on where it was playing.
The next afternoon the same account was seen playing inside of two areas that were inaccessible. One was an amusement park that had closed hours earlier and the account was building portals that aren't reachable from outside the fence. The second place it played was a public garden, also closed and the account was also capturing and linking portals that aren't reachable from outside. I reported it, and the report was closed but the account was still active.
That night just after midnight I noticed that the account was playing a couple of blocks from where I was so I parked my car on the street directly in front of the path that they were taking and waited. Sure enough the account went right by me although nobody was present. The range was such that there was nowhere else they could be but on that street to take the actions they were taking. Eventually they turned a corner. I pulled around and observed nobody present then smashed the portal they were linking from and that was it... they went dark for the night. I filed a second report which was closed.
This morning the account was spotted 800 miles north of me in another big city.
I feel like only "big-ticket" spoofing gets handled, and the rest is ignored.