I think that the biggest issue is that in many places (the UK is a personal example), the services are so utterly over stretched and overflowing capacity that there is literal years long waiting lists in some parts of the country.

In York area, unless you become a priority case due to being a risk of self/other harm then they have a waiting list of over 4000 people, with the capacity to only process 160ish per year. I'll let you figure out that maths by yourself. It's fucking hopeless. So with an official diagnosis effectively impossible to self 'diagnose' is your only option and you have to hope that the people around you are supportive enough to trust you and help regardless.

Not to mention the difficulty in even getting a referral to an assessment for the diagnosis. The steps in place are practically brick walls to us with the requirements needed to fulfill. You need to get an appointment with your GP (good luck since it's not an emergency), then you need to hope they have some understanding/experience enough to identify if you would be suitable for a referral, then you need to convince them you need a referral, then you have to wait for the specialist to pick you up and be put on the wait list, blah blah blah.

Why go through all that energy when you can just 'diagnose' yourself and carry on with struggling the way you always have. After all, as long as you keep your routine it'll be fine...right?

Except it fucking isn't, but what other choice is there?