i use it and like it alot
My feeling is that the basic mechanics of producing flowcharts, sequence diagrams and so on is simple enough that there would be plenty of software out there. The differentiators seem to be collaboration and sync tools, import/export capabilities, and pretty displays and printouts. Good integration with code generation and modeling and simulation would be nice.
I had totally forgotten that I have DIA installed on the Laptop.
I used it for layouts of 'the interconnectedness' of equipment modules, but it does have a Flowchart template.
In case anyone in still interested in Obsidian and syncing across devices (between laptop and Android in my case), I have switched from Dropbox and DropSync to using Syncthing, which is working well for me. If I am so foolish as to edit a note in both devices at the same time then it creates a conflict note which appears in Obsidian so the issue can be resolved.