What kind of SEO work is done on a monthly basis, except for the purchase of advertising, links, etc.?

Question

Search Engine Optimization

Suppose I understand that they initially check the site and optimize it at the moment, after which they begin to place meta tags, ring links and all the work that can be done "inside" the site. Let's say it takes some time. Here is the site structure, headings, meta tags, links, etc. optimized, what's next? Basically all the work is done. If you do not take into account the advertising of the site on third-party resources, the purchase of links, etc., then what kind of work can be done monthly (after all, they take money from you every month). As a result, what work can be done on a monthly basis, except for the purchase of links, citations, etc.?

Answer 1

Publishing relevant content, improving and updating existing content, analyzing competitors.

Answer 2

Yes, all the same content grows frames more and more