Crass referred to financial attitudes... a person was crass if they discussed money or one’s finances. Is this currently in use?
Not unheard of, but there are many people who wouldn't know what it meant, depending on education.
Yes, it is still and currently in use.
A cursory Google inquiry specifying "crass" within digitally published news articles, limited to the last 30 days shows an accurate usage of 10-12 examples, though this might be skewed given some recent US events.
So crude and unrefined as to be lacking in discrimination and sensibility.
It can be used to describe many behaviors and subjects. This American article Why Talking Openly About Money Is Crucial, Not Crass discusses its use. I anecdotally do remembers my 'elders' calling discussing money, religion, and heavens forbid anything about sex crass. I do not hear such these days.