A "tagline" actually makes for a great homepage title (h1) in the Modern Homepage.
Check out the Modern Homepage Showcase for some well-done examples of this.
The key difference is that this is page-specific and not site-wide.
Site-wide taglines are not included in our themes by design.
Taglines are a "default" feature of the WordPress platform (in Admin > Settings > General), originally built over a decade ago, when designs and visitor behavior was different.
New bloggers confuse the presence of this area with something "mandatory" that "must be used". This is not correct.
The only reason taglines are still in WordPress, is because removing them would affect a huge number of people. They're a legacy feature - something that exists simply because it used to in the past.
They're not still in WordPress because they provide any benefit to the people visiting the site.
Take a look at the top food blogs in the world, and you'll see that they don't use taglines.
Zero Visitor Benefit
Your visitors don't care about taglines on your pages.
For most (90%+) of food blogs, most (90%+) of traffic lands directly on recipe pages. These recipe pages have a single intent: to provide the visitor with the recipe you promised (either in Pinterest, or Facebook, or Google).
As such, your design and layout needs to be oriented around delivering that value.
Zero Search Engine Benefit
For an overview of how search engines evaluate food blogs, see: https://feastdesignco.com/recipe-page-guidelines-for-food-bloggers/
Search engines judge page quality on a page-by-page basis. Your ability to rank for a "keto sheppards pie" recipe is 99.9% unaffected by your tagline.
Taglines are typically unrelated to the content of the page. Even when they are, if your tagline was say "simple keto recipes", this tagline would provide zero benefit to search engines. Site headers are considered accessory content, which factors in minimally to your primary content.
Instead, focus on providing better primary content.
How to add taglines
You're free to customize your theme in any way you see fit, but these customizations are not supported by Feast.
For more information on what you've paid for with a theme, see: https://feastdesignco.com/what-am-i-paying-for/
For recommended developers who can implement this for you, see: https://feastdesignco.com/how-to/customization-referrals/
And as always, we recommend asking yourself: https://feastdesignco.com/why-am-i-making-this-change/