It will be interesting to see how the "noise" around ADHD and ASD develops over the next few years as research continues with access to larger datasets.
The only reason it feel like "everyone thinks they have ADHD" is because it's in the media a lot at the moment. DH and DS1 are NT, rest of family is ND.
DS2 has NHS ASD diagnosis - suspected age 2, referred to assessment in year 6, diagnosed at 14. Academically able, great imagination, chatty, small close group of friends, loves playing rugby despite hating mud. Also huge issues with autistic anxiety, struggles with relationships (none of his friends are NT) very rigid thinking, cant sense tone or read the room, massive issues with sensory overwhelm, school dyslexia screening showed significant impairments in executive function. Needs lots and lots of support but mostly to the outside world seems fine, just a bit quirky and blunt. Never applied for DLA or an EHCP for him, he will likely go on to achieve a university education and find a good job in the right industry, but daily life is much, much harder for him right now than NT DC1. This is the bit people get annoyed about - but it's not that DS1 never experiences challenges, it's just that life IS objectively more difficult for DS2 to cope with - it's never an excuse for him to behave like a dick though, he knows he's responsible for managing himself.
DS3 was referred to NHS paediatrician after his 2 year check, diagnosed with ADHD at 7, an amazing chaos demon who did not cope in mainstream despite full time 1:1 TA and now thriving in specialist school. Very bright, very impulsive, very hyperactive, currently trialling meds but no changes seen so far. Beautifully behaved, charming, well-liked child who cannot sit still and does sport 7 days per week. Unable to switch off at night without melatonin (we have tried ALL the different dietary, exercise and routine suggestions). No idea if he'll transition to mainstream following the SEND reforms. Has EHCP and gets DLA (which doesnt come close to covering the additional costs for him versus his brothers). With the right support we hope to keep him on the right path, and expect he will eventually find his place in the world through sport / the arts / something manual, with a bit of scaffolding in place.
It was through reading about how to support DS3 I discovered how ADHD can present differently in girls, and realised I fit the description well. Sought a referral, and after a 2 year wait was diagnosed with combined type ADHD by an NHS consultant psychiatrist. Meds (non-stimulant btw as I cant have stimulants) have helped a lot for work, studying and to stop binge-eating, but they cant help the worst aspects like the RSD, forgetfulness, inability to regulate sensory input, distractability and hyperactive mind. I've no need to apply for benefits for my ADHD and have not requested adjustments at work - I am in a job that suits my strengths (varied, high pressure, managing stakeholder relationships, multi-tasking, challenging, interesting work) which make up for my weaknesses (organisational skills, time keeping, going down rabbit holes, struggles with focus, following verbal instructions). I do well in work because I'm a square peg in a square hole.
This is not a fun 'label'. I'd rather not have ADHD, but I accept it's part of me and get on with life as most of us do. Benefit of diagnosis beyond the meds is that I no longer beat myself up for weeks (previously sometimes months) if I've interrupted someone, struggle with emotional regulation, over-think things etc; I've had enough tellings off for those things from other people to last a life-time, I dont need to berate myself for them too (doesnt mean I dont try really hard to manage those things though). It just stops the "why can't you just...?" comments that plagued my childhood, and helps me find better strategies to deal with things.