Name some common on-page SEO errors?

Name some common on-page SEO errors?

-Duplicate Content
-Missing Alt Tags and Broken Images
-Title Tag Issues
-Meta Descriptions
-Broken Internal and External Links
-Low Text-to-HTML Ratio
-H1 Tag Issues

Duplicate Content.
Missing Alt Tags and Broken Images.
Title Tag Issues.
Broken Internal and External Links.
H1 Tag Issues.

11 Most Common On-Site SEO Mistakes - SEMrush Study
Duplicate Content. ...
Missing Alt Tags and Broken Images. ...
Title Tag Issues. ...
Meta Descriptions. ...
Broken Internal and External Links. ...
Low Text-to-HTML Ratio. ...
H1 Tag Issues. ...
Low Word Count.