After conducting over 100 site audits resulting in 1,765 recommendations, I’d say Carol Stambaugh from RadiateWP is an expert in what mistakes are made on websites.
From user experience to accessibility to security to performance and more, Stambaugh’s Lessons Learned from 100+ Site Audits: A Peek at the Most Common Mistakes presentation at WordCamp Santa Clarita 2021 offers insights into the most common issues found on WordPress sites and how to address them.
I was disappointed, but not surprised to learn that from 100+ site audits conducted, only 11.27% of sites got alternative text for images right.
Stambaugh includes excellent resources for accessibility, legal, performance, security, and search engine optimization in her post.
WordPress Advent Calendar 2021 