Designer here: Inter is my go-to font - a free (and incredibly made!) cross between Helvetica and SF Pro! Rasmus himself has worked at his fair share of Big Important Brands (part of the original team at Spotify, worked at Facebook, NodeJS, Dropbox, Figma) [0] and it's kinda crazy to me how much Rasmus has affected me: I see the Figma icon he created every day, I see the Spotify branding he founded, I use Inter, it's kinda crazy.
Inter is the kind of font that you use when you need something that just works. Not too fancy, not too simple, it's perfect for so many things. And it's free. And it's open source [1]. What's not to like!
[0] https://rsms.me/work
[1] https://github.com/rsms/inter
Edit: it's also not a new thing, and not a 'new SF clone' - it's been around since 2016[2].
[2] https://rsms.me/work/inter/