I am sure that this idea has been posted at some point before so I'm not claiming originality.
That point out of the way, I am a level 16 player who started in 2013 left the game and then returned recently after 5 years. The landscape has changed a lot since that time, with far fewer agents in the area, and basically the hardcore's remain. I salute you all hardcores.
It's a phenomenal success that the game has survived this long. Hats off to the developers.
Now my suggestion, I think the game should have a Thanos anomaly. That is at random, 50% of all portals instantly become gray. The random factor is fair. The excitement that this will generate at least for a week or so would be of great interest to all current players and maybe other lurkers who have been holding back due to one faction completely dominating an area for so long.
If this feature works then I suggest it be a seasonal thing. Four times a year 50% of all portals worldwide, are grayed out, at random, instantly.
Then let the Rush begin.