No, I don't think that :)
There wasn't any delay in getting help, particularly with DD. it has just taken 5 years of trial and error to get things sorted.
I'm firmly convinced it would have still taken 5 years if she had started later. But sorting things at 9 has been 'early enough'. Whereas learning to read and write at 12 would have been too late. Her education would have been unrecoverable then.
Again DSs handwriting is only being sorted out now, in Y6. Which is absolutely the last time you have to sort out handwriting.
Good schools are very, very careful to make sure kids don't end up on the SEN register because they're summer born. (and not so good schools need to learn from good schools)
Extra help doesn't get thrown at 4 year olds who are behaving like 4 year olds.
I have not found lack of 'resources' to ever be the problem. Lack of knowledge, yes. Lack of aspirations, yes. Lack of long term thinking, yes. Lack of communication, yes.
But mostly lack of knowledge. Teachers aren't adequately trained in SEN.
I am sure if a child started school for the first time at 7 and shows problems, they'd still be a delay in getting them at help. The same attitudes that are trotted out at 4 would be trotted out at 7. (They need time to settle, starting school is hard, all children develop at different rates, you just have to accept your children are like that)
Certainly none of the western European countries are known for being good with SEN. Some of the Eastern European countries have excellent special schools. But I haven't heard their MS provision to be better.
(Someone more knowledgable will now come along and tell me how great country X is)