What is the most important SEO factor, according to digital marketing experts?

What is the most important SEO factor, according to digital marketing experts?

For me these are Meta tags, Heading Tags, Less load time & Mobile friendly website

SEO factors:

Optimized content
Meta tags, alt, h1, title tags in HTML
Page laoding speed
Responsive sites
Quality backlinks

Effective on-page SEO, off-page SEO, quality content & links with social media marketing are the main factor for website promotion.

The most important factor of SEO is having a rich quality content

Quality Backlinks
Page Loading Speed
Responsive Sites

Optimized On Page is the most important thing, after that backlinks to your site are quality backlinks or not?