The strong point for me is that DEVONthink uses RTF (and RTFD) as the native format. RTF is, along with Markdown, a document format that I expect to be widely s

The strong point for me is that DEVONthink uses RTF (and RTFD) as the native format. RTF is, along with Markdown, a document format that I expect to be widely supported for the next 40 years, but has the advantage of being WYSIWYG and supporting more advanced formatting. RFTD supports embedded images - it is less widely supported, but there are third party editors. The "databases" are MacOS packages, and they document how to get the files out if DEVONthink becomes unavailable. Hence for me it gives a good balance of functionality and longevity.