A sitemap is mandatory for SEO as it supports search engines like google and yahoo recognise your web site shape

https://wiki-legion.win/index.php/A_Beginner%27s_Guide_to_search_engine_marketing_Keyword_Research_Techniques

A sitemap is a must-have for search engine optimisation as it helps serps remember your website constitution, making it less difficult for them to move slowly and index your pages.