Longreads seemed to have an editorial shift a few years ago. Among other things, it no longer commissions much (if any) original stories. And the linked stories mostly fall into the personal essay camp which I'm personally less interested in. I generally liked the longform.org mix better. Sad to see them shut down.
There are a bunch of Substack newsletters that are basically collections of links to longer pieces. The one that most matches my interests is "Links I Would Gchat You If We Were Friends": https://linksiwouldgchatyou.substack.com/. The only downside is that it doesn't publish that frequently.
Literary Hub's weekly roundup is another good source of essays that take maybe 10 minutes to read. I find the meat of the newsletter is the bottom where they link out to excerpts from new books. https://lithub.com/. One good example: "Did the Russian Wizard of Oz Subvert Soviet Propaganda?" https://lithub.com/did-the-russian-wizard-of-oz-subvert-sovi...