Autism

Depends on your country, I guess. If your country has additional benefits, rights or support to offer then you need an official diagnosis to access them. That's the case over here in Sweden. If you're American though then sure, I assume that part of healthcare and social security is completely absent.

Ultimately though yes, much like the definitions for personality disorders, the dividing line is generally whether it negatively impacts your day to day functioning. If you don't feel any negative impacts on your life as a result of how you are then you don't "need" a diagnosis.

It could still help you understand yourself better though.

ADHD diagnosis helped me get meds and they have made a big difference for me.

Autism diagnosis makes it so you can request a GDB (Grad Der Behinderung) in Germany which gives you certain benefits. I didn't make my autism diagnosis "official" with my healthcare provider tho as I am aware of potential stigmata regarding potential future fascist governments. Also I have heard some horror stories about autistic people being denied gender affirming surgery.

Concentration camps. Probably.

Depends entirely on how much you struggle. Diagnosis is useful for knowing what kind of help to get. If you don't struggle, but only see some kind of behavior patterns that might occasionally cause problems, you can just try to address those individually.

I have a diagnosis for BPD, which was useful for getting treatment and ultimately, financial support. These days however I don't agree with the diagnosis and rather think I'm somewhere in the BPD/C-PTSD/Autism neighborhood but I don't really need a clinical diagnosis for any practical purposes.

These are all just words that people made up, that reflect a cluster of patterns with great variability between individuals. They're not absolute truths. Just tools to help navigate whatever system one finds themselves in.

On most days, the piece of paper is just that; paper. But if you need medication, psychological counseling, or an accommodation for work or school, that piece of paper can be quite useful. On average, I feel like it is better to have it and not need it, rather than to need it and not have it.

Nested parens? Yup, you're on the spectrum.

So am I, didn't realize until I was old. No need for me to get a diagnosis; I have also settled into my ways. I just understand them a bit better now, and I'm okay with "being who I am". However, a lot of that came because my kids got diagnoses.

If you're young(ish), and don't have a solid clinical understanding of how autism can manifest, a diagnosis for you might be useful - but you can also acquire that additional information independently. Just make sure you're researching at legitimate sources and not what randos on the internet say.

Being told I'm on the spectrum, by a medical person was like.

Oh

I'm not a weirdo for no reason. I'm not being picky because I can't stand certain fabrics. I'm not being an asshole (...debateable) for being overstimulated without words to explain it. Those other children were being dicks to me, it wasn't just me being sensitive.

A relief. Not much of one, but I cling to it.

There also exist mental problems like being a dismissive avoidant(DA) attachment that can masquerade as autism, so making sure that it is not something else that can be treated away can be beneficial, you might even be a DA and have autism. So getting the DA treated would most likely help you in every day life

Talking to a psychologist might help you to understand yourself better and maybe help you develop strategies to cope better with certain situations. So it may well be worth it. If certainly not a silver bullet that will "cure" you, but it might be useful. Whether that's worth the hassle to you, is entirely your decision.

I do struggle to justify it when it's not covered by universal healthcare like mine was

For me, it was access to “free” Medikinet (paid by mandatory health insurance)

A formal diagnosis can help you get meds, which could help. But it won't change how mustard tastes. It's up to you.

I also wouldn’t say, that they cause any sort of “day to day problems” for myself.

Well then you wouldn't qualify a diagnosis. A competent diagnostician would say that you do not have ADHD or Autism. You may have some neurodivergent tendencies without being categorically classified into one of the diagnostically-labelled neurotypes.

But I guess your question is why to do it at all? Getting a diagnosis helped me focus on exactly where to put my efforts toward managing my life. Very worth it for me. Suspecting I was autistic was all well and good, but the idea that 'maybe I wasn't' was a bit of an obstacle to moving ahead with certain changes.