Some HN links from just today that do it https://fullstackeconomics.com/why-america-cant-build-big-things-any-more/
https://patrickcollison.com/fast
https://gankra.github.io/blah/fix-rust-pointers/
https://gashamola.com/2022/03/16/the-elephant-in-the-event-loop.html
And just for a nice change here’s a link that acts as you would expect
https://migrant.substack.com/p/how-google-fi-suddenly-struck?s=r
More widely, from a UX perspective its use, as with any action the user can perform, should be clear on what to expect: e.g. using iconography that hints the opening is going to be in a new page, whether the link is pointing to a different domain, and stating what the link is about (i.e. no use of "click here").
This might not have been a conscious choice by the website designers, so not explaining why this is happening on those sites, but I hope it adds to the discussion.