The fediverse is not really a popularly known thing outside of geek and crypto circles, anyway. Unless that’s your target audience, I think the fediverse is going to make it too complicated for regular users to read your blog.
“Decentralized” software tends to mean “forks into multiple different things maintained by ideologically different parties” eventually, and intercompatibility is not always guaranteed.
Almost certainly by 2040 it’ll be something entirely different (but that’s the case no matter what platform you choose now… 2040 is an eternity in technology time.) I’d be surprised if anything popular today even makes it to 2030. Wordpress might (the recent drama puts it in doubt). Wix probably will, on sheer momentum. Various federated, decentralized services…? I wouldn’t count on it.
Sorry about the Wix dashboard performance. I guess if you’re on a slower connection or computer, that might happen. Are their published sites (like the ones in their template gallery) slow for you too?
Squarespace and Weebly are other similar page builder services. Google Sites is fast but looks fugly and doesn’t leave you any room to grow.
Wordpress.com is a commercial service that’s going to try to charge you at every opportunity. Wordpress.org is the free version that you set up yourself. wpengine.com is another paid host, but they are the ones under attack by Wordpress itself. There are other such hosts out there, like Dreamhost, Bluehost, Kinsta, Pantheon, etc. at various price points. Cloudways.com lets you deploy wordpress.org (the free version) to a cloud host of your choice, like Amazon or Vultr or DigitalOcean. This is usually cheaper than hosting directly on a Wordpress host. GridPane.com is a DIY clone of Cloudways that’s even cheaper. Generally, the less you pay, the harder it will be to set up and maintain, but those tools make it slightly less painful.
Wordpress can be extend to have page-builder functionality (including carousels, etc.) with paid add-ons like https://www.wpbeaverbuilder.com/, https://elementor.com/, or https://visualcomposer.com/. However, those aren’t really based on any web standards; they’re just their own thing that some small company invented specifically for Wordpress. They’ve been around for a while (especially elementor and visual composer) but there’s no guarantee they’ll survive into the future, especially if Wordpress gets forked.
This is one of those “easy, fast, cheap – pick 2 (or even just one)” situations. It’s an oversaturated space with a lot of mediocre options with various tradeoffs, but no one perfect, one-size-fits-all solution. It’s pretty much one of those things where you just have to try a bunch of different services until you find the one you hate the least.
You can also consider paying someone to build this site for you using actual web technologies (HTML, CSS, maybe a modern “framework” if needed). There are various adjacent systems that would allow you still easily edit such a site once it’s built (like Markdown or headless content management systems), but you won’t be able to easily add your own new features or upgrade the site to a new platform without further paid help. It does stand a better chance of being around for the long haul though, since it’s just normal web stuff and not a bespoke page builder system. It also makes hosting very cheap.
Might be the case where you can pay someone a couple hundred bucks, get a good enough site up (especially if you pick from an existing template) and then have free or cheap hosting that pays for itself over several years.
An example of such a system might be something like Astro (or see their free blog themes). An experienced developer could set that up for you in a few minutes, and you’d edit your posts in Markdown from then on. It’s easily hostable anywhere, including for free or very very cheap, and would be easily portable to other systems later. The downside is that it’s actual code that you have to hire someone to set up (or learn to do yourself), not just a service you can push a few buttons for and start typing.
If all of this is too much detail (sorry about that…), really, just try a few of the options and see which one you hate the least. They’re all good and bad in their own ways and only you know your specific preferences.