I mean not sure you'll accept my answer but I'm 26 (turned 26 last week). And I feel like a young adult. I have two degrees, own my own home thanks to my partner and our parents (he earns 5x my amount but is my age), been with my partner for eight years.
And yet when I finished my MA, to get a job I had to do an apprenticeship. Nobody else would accept me without 3-5 years experience.
So I got my first full time, properly paid job, at age 24. Before that I was offered unpaid or £16,000 a year in London. Nobody else was interested despite the pact I've worked since age 14.
25+ is an adult, but not like it was 30 years ago. The working world beats you down. I applied for over 500 jobs with a MA degree and having worked in pubs, bars, Oasis since I was 14.
They don't care.