Are H2 tags important for SEO?

If there will be no sequence in your post, then both your users and Google Crawlers will not understand your post, so Header Tags are very important.

Whatever your topic is divided from H1 to H6, then a structure of your post or page is ready. This type of structure is considered an ideal structure for your post. Header Tags are also very important from SEO point of view.

Yes H2 tag is important for seo.

Yes, H2 tags are very important, as they help to break down content in sections with further sub headings which help search engines to create rich text snippet .