Plume is the main fediverse blogging application but I don't think it's actively maintained.

Micro.blog offer a paid-for service (starts at $5 a month) and the blogs can be federated.

Honestly writefreely can be as elaborate as you want it to be if you self-host it. There are lots of options under the hood as well as the CSS being fully customizable. I host my own with a single core, 1GB of RAM and 16GB of storage and even that is overkill as pictures and videos are just embeds from other platforms. Plume is deprecated, and micro.blog is paid and not self-hostable. There is microblog.pub though which I haven't tried yet but looks promising.

Yeah is something I've been keeping an eye on. I don't even dislike WordPress, but there's a lot of clutter on your blog unless you're running Firefox and uBlock. That said when I look at write.freely articles, they're just a title and text. I've never seen a logo, header or imbedded image and £6 a month to host maybe 3 posts a year seems excessive.

Just another option. If you know already or are willing to learn how to write documents in markdown format (like how lemmy supports), and learn some of infrastructure set-up and it can be between free and very cheap to have a blog on something like netlify.app, github pages or others. There are plenty of static site generators out there that can be both relatively easy and very powerful.

I currently have a private blog set up on a cloud provider that just takes markdown documents and builds those along with some templates and webpage code to create a site like this. Although I have mine hosted on a VPS with my own domain, it's completely possible to use something like github pages, netlify.app, etc. for that. They're both free afaik to host on, but if you want to pay for a dedicated service they are usually between 2 and 5 USD per month.

Edit: The option above isn't activitypub software, sorry for not realizing that immediately, but it is federated in a way I suppose.