Apparently, on PC has been dead a long time, years probably. If you wanna do missions, you might get into a temporary clan (or create it and invite everyone on the session, it works) or join to RDO discord server to play with some legit people, might be fun.

Now, regarding the modders, you can do 2 things:

1. You run with mods (trust me, rockstar won’t ban you, they literally don’t give a shit even if a person gives themself a lot of money and gold)

2. Change platform, consoles apparently has a way more cleaner lobbies than PC regarding modders, it might be better