I mean, the rich drug dealers you know are rich from dealing, aren’t the ones to have that lifestyle long term.

The sensible and rich drug dealers are the ones you wouldn’t know about. Quite a few of them are landlords here in the UK (I can’t provide numbers, just a what I know thing so I won’t be offended if no one believes it - these are just my ramblings, officer).
Basically just sensible ways to turn black market income into seemingly legitimate income, through either self-employed businesses or other means.

They’ll have seemingly regular jobs, and will do their best to appear legitimate to not raise any red flags. You’d be very surprised at who the most successful drug dealers are, however chances are you’ll never know as well.