Maybe, but many of their fans aspire to the 70s image.
I live over 2 miles from the ground, and I can get a bus there(probably won't be allowed to for the return journey). I lived in many parts of south London and know and have known many Millwall fans. So, yes the Millwall of 2020s comes to mind. They're not the knuckle draggers that 1970s documentaries about hooliganism screened when Millwall was mentioned. However, the nearer you get to South Bermondsey and the Den, the "tougher" Millwall fans become. They can be polite people off matchdays, but come matchday, that nice young man in the office is suddenly chanting racist abuse and threatening violence to opposing fans. Yes, all teams have these fans. It's just that Millwall have a higher proportion of them in their fan base. So, it's right to be wary: they are "hard" in their neck of the woods