Does structured data effects SEO? I mean they effect SERP CTR but does have any effect on SEO too?
Using structured data correctly can help search engines to better understand what your content is about and may therefore contribute to a stronger relevancy signal. In addition, studies have shown that rich snippets can improve click-through rate (CTR), which can lead to better rankings indirectly.
They don't effect directly to SEO. Some might say no effect.
They just helps increasing CTR.
Some might also think that higher CTR may effect SEO. But its not atleast not to some point.
Structured data are not a ranking factor. In other words, implementation of SD does not guarantee the ranking boost. However, structured data may help Google to better understand the page content what may make the page more relevant for search queries.
It helps search engine to understand the page of your website in a better way but it does not affect the SEO directly.
Structured data helps to increase CTR. But it does not affect SEO directly.
Structured data does not help to improve your ranking
Structured data does not help to improve ranking
Indirectly they may help but not directly.