I would not be surprised if there was a group using this approach, but I doubt most of them are/would. If they were that dedicated, they'd just have a fucking job, instead of being dicks on the internet for a living.
However at this point: every developed nation has a professional offensive security group that have varying degrees of potency. All are more resourced than 99.9% of organizations defending and enjoy legal autonomy in their country and allied countries for their work.
If you're getting salaried comfortably, and you have near infinite resources, a two year timeline is trivial. As an American, I always like to point to things we know our own services have done first[0].
Each actor group have their own motivations and tactics[1]. As someone who spent a lot of time dealing with a few state actors, you learn your adversaries tricks of the trade and they are patient for the long-con because they can afford to be.
[0] - https://www.npr.org/2020/03/05/812499752/uncovering-the-cias... [1] - https://learn.microsoft.com/en-us/microsoft-365/security/def...
As someone that's spent a lot of time in darker places, I would agree.