HTML defines six levels of headings. A heading element implies all the font changes, paragraph breaks before and after, and any white space necessary to render the heading. The heading elements are H1, H2, H3, H4, H5, and H6 with H1 being the highest (or most important) level and H6 the least.
Use the semantic element of HTML5 such as ARTICLE and/or SECTION together with header elements when you want to make the hierarchical structure of a document explicit. This is needed as header elements themselves only contain the text of the header, and do not imply any structural division of documents into sections.
Source Headings of W3.
Verify the hierarchy of html on the HTML 5 Outliner:
The guide of Google Search Engine Optimization (SEO) Starter Guide informs us:
Use heading tags to emphasize important text
Since heading tags typically make text contained in them larger than normal text on the page, this is a visual cue to users that this text is important and could help them understand something about the type of content underneath the heading text. Multiple heading sizes used in order create a hierarchical structure for your content, making it easier for users to navigate through your document.
The semantics HTML5 of which the elements heading (including the element H1) are part is applied to WAI-ARIA for accessibility users with disabilities to the contents of web pages. The documentation of W3 HTML 5.2 W3C Recommendation, 14 December 2017 tells us:
This semantic information is critical to assistive technologies. For example, a screen reader will query the browser for semantic information and use that information to present the document or application in synthetic speech.
In some cases assistive technologies use semantic information to
provide additional functionality. A speech recognition tool might
provide a voice command for moving focus to the start of the main
element for example.
When the appropriate HTML element or attribute is not used, it deprives HTML processors of valuable semantic information.
In addition, the hierarchy of your web pages can help you in getting Featured Snippets in the SERP of your website.
Read more A Simple Process To Find Featured Snippets Opportunities of Ignite Visibility.
So my answer to your question: The use of the H1 element and other elements of heading can is valuable for search engine optimization if this is used in conjunction with the semantic HTML5.