Handwritten Notes offer significant advantages in a lot of use cases. They are fast, easy and distraction-free while also never running out of battery. Plus, you can format and arrange your notes however you like.
Of course, they don’t offer backups, automatic reminders and search/share features. But this might be fine for your short-term or spontaneous notes. Also, it might help you remember your notes better.
Standard Notes is a simple open source notes app focussing on simplicity. By creating an account, you can easily sync your notes across devices with end-to-end-encryption.
Advanced users might be interested in the paid extended version or in hosting the sync server themselves.
Joplin is a libre note taking and to-do app. Notes are organized into notebooks and can be searched, tagged, exported and synced across devices.
If you are using Nextcloud, the Notes extension is a good option for organizing your notes. You can edit them with every Nextcloud client and many third-party apps.