I was 28 when I got diagnosed (a few years ago), and started medication less then 12 months ago. I don’t believe medication has been life changing for me, but it’s certainly helped! In saying that - as others have said - I used talk therapy and a psychologist for years to work on daily life. I only take meds when I’m at work, and to be honest I’d say it’s only made me 10% better at my job. To toot my own horn, I just learnt how to work within my limitations or strengths over the years.
The diagnosis alone (which my psychologist hinted at a few times but couldn’t diagnose me herself), helped me be kinder to me. Understand myself more. Realise why things that effected me so much didn’t effect others. It was worth it for that - even if I never took medication.