https://www.pcgamer.com/gta-5-executive-business-mod-brings-online-enterprising-to-its-singleplayer-mode/

There are a number of ways to make money in GTA Online that require skill, finesse and, sometimes, simply signing in. Success, however, is often determined by the folk (read: infuriating griefers) you're forced to rub shoulders with in public forums. 

With this in mind, HKH191's Executive Business mod takes GTA Online's CEO business ventures offline, and into its singleplayer mode. Griefing problem solved.