huge obsidian.md fan here. it doesn't have a web editor, but since your notes really are just markdown files it's easy to mix and match with other markdown editors. for quick notes i like to drop into markor on my phone rather than obsidian, since they're compatible and obsidian takes longer to load due to my love of plugins
i use syncthing to get my vault onto all my devices on the fly, plus a git repo for longer-term archival. i believe syncthing doesn't play so well on ios due to system limitations, however, so using the official "obsidian sync" service might be a better bet in your case?