The reason there is more autism DIAGNOSIS is that we know about it more now so we are better at assessing and diagnosing it. The same amount of people still have autism as before but the people were much less likely to be diagnosed back then. There are a lot of adults now discovering they are autistic that wouldn't have been diagnosed as children. Some find out when life gets harder. Some get help for one thing and eventually it gets found it. Some work it out themselves and seek help and an assessment. Some get diagnosed after their child or grandchild is diagnosed.

Being "missed" and remaining undiagnosed for a long time is even more likely to be the case when people are of a different race or sex to those that tend to be associated with a particular disorder / disability / health issue / neurological difference. Nothing changed inside those adults due to vaccines that made them suddenly autistic - they were autistic their whole lives and it simply wasn't discovered at an early age. We are getting better at assessing and treating things. It's due to an increase in knowledge.

We are also better at assessing kids now. Kids who would have been missed in the past (especially girls) are more likely to have their autism noticed earlier nowadays, which is a good thing.

I think it's great that less people will have to suffer being undiagnosed or misdiagnosed in the future and can get help earlier in life.

Vaccines are not the cause of this - having better knowledge and being better at assessment and diagnosis is.

To be fair, there are very very rare situations where people either have a bad reaction to a vaccine or are allergic to individual ingredients in it, but that still doesn't cause autism. That's simply not how that works. The thing is though, that the people who can't get it, stand the most to benefit from the people who can get it, getting it.

Either way, I've seen anti-vaxxers say that their child dying of a deadly vaccine preventable disease is better than their child being autistic and that's incredibly disgusting. I know you are not saying that, but choosing not to vaccinate over autism is still putting a child at risk of dying from a preventable disease simply to avoid having a disabled or neurodiverse child which is misinformed and definitely disturbing.