Please, just stop using such clear-cut language in relation to ASD. There's nuance and people need to speak to a consultant or a lawyer about it. But you can't just sit back and say "Oh, the person can take an advanced diploma, so they must be financially independent." It's not uniform, it's not standard, the ASD spectrum is different for each person.
Depending on the intended province of establishment, things like group homes may not even be paid by provincial health care, reducing the claim on public services. There's so much nuance and challenge that trying to dispense answers on an internet forum about anything to do with independence and ASD is absolutely pointless.
Parents don't always "choose" group homes. Many families cannot access them, or do not want to access them, preferring to conduct care at home. If a family can afford it, then that's fine. Each case is different.