A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Hi Brandon,
First, I'd like to confirm whether you are using the new Communication site or a Team site, this is because the feature isn't available to Communication site. But you can vote this post in UserVoice: In SPO, enable the option of activating SP publishing infrastructure feature in Communication sites to submit your feedback and help us improve our product.
If you are not using the Communication site, we'd like to explain that the feature needs to be activated in the site collection level. You can go to the Site settings, check if there is "Go to top level site settings", follow the link, then in Site Collection Features, to activate the SharePoint Server Publishing Infrastructure.
Regards,
Tisky