Oh yeah, forgot that.
For Austrians there is Willhaben, which of course is not federated, but is already really good.

Since by default you can't upload pictures in full HD and you also can't upload many pictures at once, I'd say no.

Interesting, I didn't know about these limitations (don't actually use PixelFed myself). I would assume these are just “default instance settings” rather than something intrinsically limited at the platform level, though? Meaning: could someone set up a PixelFed instance where the original photos are preserved and upload limits are lifted just by changing some configuration parameters?

The max image size can be changed at instance level, but last time I checked that didn't really work for very large pictures.

About multiple images: I misspoke. You can upload multiple images in one post and you can change how many at instance level. What you can't do is upload multiple images at once with one post per image.
And scrolling through the images in a Pixelfed post is not as smooth as in a Flickr album.

But yeah, it would probably be possible to fork Pixelfed to create a Flickr replacement.

In the mean time I've discovered that apparently PeerPx https://github.com/peerpx/peerpx aims at being a Flickr alternative. Still work-in-progress though.