Jekyll can set the basics such as meta descriptions via YAML front matter and the page template system, custom page titles, custom URL structure, etc. You can also use proper formatting quite easily (h1, etc.) with your choice of formatting.

As long as you have that covered that is all you really need for good SEO - the rest is keyword research, quality content, links, etc.

In my experience it works great for SEO: you're in control of basically everything, so you have the freedom to play with meta tags, sitemaps, structured data, readable urls and so on.

But, of course, afaik, there's no plugin with nice explanations and checkboxes to configure that stuff.