Illager patrols spawn in unreasonable places( this can be explained by old world?), their spawn rate is huge also. I often see groups of 10+ or even 20+ illagers with few banner guys. They also don't seem to despawn. All illagers in screenshots were in unloaded chunks for more than 30 minutes. For this time only I was online and used my spectator account to take those so it's not possible for any new illagers spawn.