Notesnook

Yes. The free plan has unlimited notes on unlimited devices with encrypted sync. It allows 50 MB of uploads a month, files up to 10 MB, and 50 notebooks and 50 tags. The paid Essential, Pro and Believer plans raise those limits and add more storage.

Notesnook is open source under GPL-3.0, including the apps and the sync server. Notes are encrypted on your device with XChaCha20-Poly1305 and Argon2 before upload, so the server only holds encrypted data. You can also put notes in a vault with its own password.

Download the DMG for Apple silicon or Intel from notesnook.com/downloads, or run brew install --cask notesnook in Terminal. Drag the app to Applications and open it.

Neither the Notesnook download page nor the Homebrew cask lists a minimum macOS version. There are native builds for both Apple silicon and Intel Macs.

Both use notebooks and tags, and both have a web clipper. Evernote's free plan stops at 50 notes, one notebook and sync on one device, while Notesnook's free plan has unlimited notes and devices. Evernote lists in-note encryption for Mac and Windows; Notesnook encrypts every note end to end by default. Notesnook can import your Evernote notes.

Yes. Notesnook calls these Monographs. You can publish a single note as a web page and add a password if you only want certain people to read it.