It depends on the allowance or the way it's managed. In 1993/1994 my father allowed my mum £100 a month non negotiable, to be spent on what he allowed only. That money was for food, clothing, transport, leisure, school equipment, medicines, etc etc.
I won't write lots of details but I didn't try fresh food until I was about 8. We couldn't afford it. I didn't get brand new clothing until a similar age. Prior to that the lot came from social services. I did not realise shampoo and bubble bath came in different scents and colours - I was brought up with white red and blue tesco bottles of everything.
My father had at the time a top of range PC, pager, mobile phone, sky digital, basic internet, answering machine with phone hold system, car, caravan, boat. Because he didn't put his money into the 'pot' as it were (the 100 was mums 'invalidity payment') he was able to have a very good standard of living for himself.
He did buy holidays in the UK - we had one absolutely wonderful holiday, as odd as it might sound, and he bought my sister and I some toys for Christmas.
It was all very controlling - from the outside, we looked like we had money to due what was parked out front which stopped people, literally, from getting too involved. He had my mum on a strict routine with money and she had to ask for it - like he was a bank manager or something crazy like that. Very much one in charge of the other.
It wasn't isolated either - my father was also sexually, physically and emotionally abusive. Like PPs have said it probably all ties together.
If however my father had taken control of the finances with negotiable, mutual agreements - and if he'd allowed us to have normal food, toiletries etc and not spent all his money on himself, he wouldn't have been financially abusive, I think.