Some people lose their phone, others get a new job - and some people just cannot remember the email address. Without any possibility to remember the password - or having just caused account lock by trying to guess the password - and without any backup access token, the blog is lost, for good. Right?
Yes, and no. The blog can't be updated - but it can be read.
If you absolutely can't recover control of a blog, and you want to keep publishing similar content, use the Blogger option.
Number of Blogs: You can have up to 100 blogs per account.Make a new blog. Blogs are free.
Make the new and old blogs part of a blog cluster.
Having started a new blog, keep the old blog, read only - and make the two blogs part of a blog cluster.
With enough imagination - and use of the Pages gadget, iframes, and maybe a template copy - you can make the two blogs look pretty much like one blog. You won't be able to link from the old blog to the new blog, so work on keeping all of the visitor traffic in the new blog.
As with any new blog, you have to start from the beginning.
You will have to get the new blog indexed, and starting with no search reputation. But if you plan, you can make that work.
It's certainly a better idea, than starting from zero, completely. And it's more productive than giving up, because you can't use the recovery tools, successfully.