I've known since DS was tiny that there was something not quite right with him. At toddler group all of the other children would be sitting singing nursery rhymes while DS would be literally climbing the curtains or at the reception desk trying to work the photocopier or sitting on the knee of some random, cuddled in and chatting away like he'd known them for years. The old stereotype of ASD is someone closed off from the world but DS is the opposite, he's too open to it. He seeks constant sensory input, has no sense of boundaries or personal space, and no sense of risk or danger including stranger danger. He frequently goes into sensory overload and will then have a meltdown during which he can be violent to himself and others.
Fighting to get him assessed has been a long and frustrating process. I highly doubt that anyone goes through it purely for access to benefits or as a cover up for shitty parenting - I've seen both of these ideas expressed on this thread and won't quote the two posters who made these comments because their comments are, frankly, bullshit.
Our experience of the assessment process was years of "wait and see" followed by "he'll grow out of it" followed by "some children are simply highly strung". Then we had the early stages of the assessment process during which our parenting and his development were picked apart. Then the school nursing team came along to go over the same things. What are your concerns? What have you tried to correct the situation? How did that work out? What's he like in school? At home? In public? And so on and so on. He was more or less coping at school so alongside this we had school refusing to acknowledge there was an issue despite him seeing SALT for garbled/rushed and repetitive speech and being in the early intervention group for handwriting that was a vague scribble. Then, finally, a referral to CYPS.
It's horrible. Really and truly horrible. I feel like I spend every meeting slagging DS off because we talk about the concerning behaviours. I could write a list ten times as long about all the ways in which he's wonderful but it wouldn't cancel out the myriad of concerning behaviours. I come away from meetings feeling so negative because we've been discussing negative things.
I'm not at all surprised some parents don't want to pursue a diagnosis. There have been times that I've wanted to call the whole thing off, where I'll worry if I'm doing the right thing by DS, where I'll think maybe he is just quirky or high strung, maybe it is my parenting and I'm just a shit mother. I worry about the impact it'll have on the rest of his life, how he'll be perceived by others, and so on.
The reason we decided to seek diagnosis was that he was getting worse with age, not better, and we felt we needed access to the relevant support. If a child is stable in terms of their development (for want of a better term) and coping well with their day to day life, the parents are coping with it all, and everyone is happy then what would the point of seeking a diagnosis be? If their situation becomes problematic in future then they could seek a diagnosis then. It's not necessarily denial to delay it.