There are a lot of websites out there. Just to show how fast the internet is growing, Techradar says that there are more than 547,200 new websites every day. Imagine how many more sites will exist in just a week at that rate.
For Google, it has to crawl each and everyone of them, storying information in their database. Because this data can be stored on a finite amount of server space, Google has to be a bit picky to say the least. It has to prioritize well designed and fast sites that can provide the information people need when visiting those websites.
This is why technical SEO audits are important if you want to be sure your site is one of the ones prioritized by Google when getting crawled.
A technical SEO audit is a process that checks various technical parts of a website to make sure they are following best practices for search optimization. This means technical parts of your site that relate directly to ranking factors for search engines like Google.
If you want to know what goes into a technical SEO audit for a website, check out the article written by Marcela De Vivo over on Search Engine Land for details.