It looks very nice and professional. It doesn't break in my browser.
The use of "Username is a" forces the use of a non-vowel starting word in the users description of themselves.
The photo doesn't stay in the original aspect ratio, which I can work around, but it would be nice to avoid that surprise.
My email doesn't show up on my page
I do like the Oauth signup, instead of yet another password to get compromised.
[Edit] - 3.3 Megabytes of code for my page is quiet a lot. However, the real danger for you is that profile pictures aren't scaled, and seem to be stored at original size.
None of the above is unfixable... I'm not trying to crush any ambition.
It looks even better in Dark mode, which is how I tend to browse,
The value is a single source of truth...if you were to add a page on your blog you would have to take care not to change the link in the future...this is not the case here.
Plus this is not only for developers.
But we have control over our own blogs and URLs. We have no control over you shutting down your site. That value prop feels like a big stretch.
Your site itself is fine... you just haven't yet solved a problem for most people in a new way, so you need to keep working on it to figure out what unique value this can have.