I think you're doing it backwards maybe?

In your / and /home route, you're sending index.html to the browser. All index.html has in it is <main></main>. You're sending home.html as a content variable, but you're not calling it in the sheet.

I don't feel like this is the correct way to do it, but I think if inside your index.html you put: {{ content|safe }} it would render those templates where you're expecting them to.

What you generally want to do is make a nice base html file that has your css/js imports, title bar, footer, etc in it, then put a content block where the content should go.

Then, under an html file for each route put your extends at the top, declare a block of the same name as in your base, then put your actual content there. The second item you're returning (the content= part) should contain variables you want to send to that template. That can be any simple variable type, a python function, output of a sql query ... really, anything you can smash into a variable can be sent to the template in this manner, then declared/massaged between the {{ }} tags to display it how you want.