Cool Urls don't change
If you're running a personal blog, you might get tempted to switch between tooling often. There's so many shiny platforms! It's way easier to go between write.as, ohai.social, bearblog, 11ty, astro and back again than it is to sit down and actually write something. Now, while that's a futile endeavor and often a huge waste of everyone's time, I'm not here to talk about that. If you wanna switch blogging platforms, do that. But please, oh god please, stop switching up your domain and url structure for no good reason.
If all your posts are at /blog... keep them at /blog when you switch. If your url structure is /dd-mm-yy/post, keep doing that. I do not care what your url structure is. Noone cares what your url structure is. It does not matter.
"Oh kami, the blogging tool I use enforces a different url structure"
That's fine. You can set up redirects. Make a couple custom pages for your previous posts, have them auto-redirect to the new version. If your blogging tool does not let you do at least that much, you should reconsider using it.
If you want your blog to be read (which, if it's visible enough for me to find and read it, you probably do), it's just a bad idea to keep switching up your urls. It is really annoying to deal with, as a reader. It does not provide any benefit to anyone.
Please stop speedrunning link rot. Cool Urls don't change - if you're not gonna take it from me, you should at least trust the w3c.