Self hosted WordPress is a good option over Blogger for many reasons.
SEOWordPress allows you more control over on page SEO which you can't have on blogger. For example, you don't have control over the permalinks and the robots.txt etc. Make sure you use All in one SEO plugin. Avoid Yoast SEO plugin because there are ads and constant popups of premium version is included.
Writing & Formatting WordPress has lot better text editor options for media support such as twitter and YouTube videos. In case of blogger you can't add twitter or Facebook post inside the content. Also WordPress has zen mode for distraction free writing. As you can see it has lot of writing options such as that and in next version the editor will be similar to Medium.com
Themes As far as themes are concerned WordPress takes the edge. You can use page builder like Elementor and you'd be able to get more control over design aspect. And that's one reason you'd find many bloggers on blogger are struggling. It is not a flexible editor on page you get at blogger.com
Plugins WordPress has better plugins and you can easily edit them to customize as your own. Compared that to blogger which has nothing. So you can guess you'd have more work on blogger and less on WordPress based platform.
So if you have long term plans for blogging and design, then WordPress is a good choice. If you just want some platform to write and do nothing much other than that, then blogger.com, medium.com and wordpress.com all are equally suitable.