Migration from Blogger to WordPress is good, because there are lot of advantages, like you will get the full ownership of your blog, you will have no traffic bandwidth, lots of themes and widgets etc. So future of your blog becomes better but after migrating from Blogger to Wordpress you can face some problems that I am going to mention below.
My case was I started blogging on Blogger platform in 2013 with a custom domain name which I bought it from Godaddy and from very first year I was thinking to migrate it from Blogger to Wordpress but due to some confusions I always ignore to do. Finally in 2017 I took the decision to migrate it to Wordpress and finally I did that. But before doing it obviously I read many blog posts to accomplish this task.
So after reading it I was thinking that OK I will not loose any search traffic and will face no any issues. And after performing all the migration steps I got the following issues which I was not expecting.
Problem (1): Most of the blog post's URLs have changed because sometimes it is not necessary that you keep same URL as the post title. So I got many 404 errors.
Problem (2): I imported my blog posts from the backup XML file but NO any descriptions imported means all blog posts were without meta descriptions and keywords which is a big drawback for SEO.
These above two problems are the major ones but it does not mean that it is not get resolved, I solved it by modifying blog posts and specified meta descriptions and meta keywords and by submitting new sitemap to Google Webmaster etc. But the problems were there which can not be ignored.
So I just want to make you aware that migrating from Blogger to Wordpress is not that smooth, you can face some challenges / problems but would be sorted out after sometime. I mean the lost URLs will started hide from search results after sometime and manual action to add meta descriptions will solve the problems.