I spun up a test Wagtail install and followed its tutorial which lets you make a basic blog with categories, tags, galleries. The interface looks good on screenshots but is a bit unpolished in places, I tried installing wagtail-blog as well but it’s written for v2 and we’re at v4 now. That could be quite easy to update, I haven’t checked but might do, depending on motivation.
That said compared to the tutorial creating RSS feeds is not too hard, a WordPress Importer would be nice.
After that investigate some indieweb features.