If a 17 year old behaves like an adult, taking responsibility for their own washing, cooking, spending, bills, earning then yes. Otherwise they are treated how they act... My 15 year old is quite adult.
I have a 17 year old. She is well on the way to adulthood and as such I feel that lots of decisions about her life are hers. She has partly earned me feeling this way as she holds down a job - full time over the summer-, has a responsible attitude to her education, finances all her social activities and her ballet, and pulls her weight with the housework at home. However, she's not legally an adult until next year (also a 1996) and even then she has a lot to learn, particularly about how tough it is to finance yourself through life. I still give her guidance and support, which I suspect she will need for a good few years to come. I would also not be scared to put my foot down and insist she did or didn't do something if I thought she was in any danger or doing something very irresponsible or stupid.
From the perspective of a mum with a 15 year old and an 18 year old I would say that there is huge variation in maturity. Legally 18 is the point at which one becomes an "adult" and can do things without the permission of a parent.
Practically there is a huge difference between our son at 17 and now at 18. Our dd is very mature in some ways but quite naive in others.
I think 17 year olds are young adults who have a lot to learn practically, emotionally and intellectually. They have the capacity to become very sensible, mature, capable adults but still need a lot of gentle guidance in order to do that successfully. The more mature a person, the more they will anticipate danger and realise their limitations.
Are you having a problem with your mum at the moment OP? Are you OK?
For me, adulthood is when you become self-sufficient! You look after yourself, pay your own way and don't expect your parents to support you financially or practically. I've known 16 year olds who have become adults, many are much older!