I just found this artist on Pixiv with full of amazing wallpaper, like they are so good it's unfair

https://lemmy.ca/post/52553465

Is there some other way to browse Pixiv or the posts made in it, like through third party interfaces (e.g. Nitter for Twitter), RSS bridges, bots in social medias (for tracking new posts), etc.?

Used Pixiv for a while, but found UX pretty bad, doom/endless scrolling style, and would rather not use it directly if possible.

You could check out PixivEF, as well as Pix-EZviewer. They are both open source frontends for Pixiv. Not sure if it fits your needs but they are decent options
PixivFE

An open source alternative frontend for Pixiv

Codeberg.org
Will check! Thanks!