[[foam]] seemed more easily extensible to me, but [[obsidian plugins]] (community maintained) tend to be great and open source.
[[obsidian git]] is a great [[vault]] backup solution and open source. It replaces proprietary [[cloud sync]] — which you need to pay for if you get it from [[obsidian]] directly.
as of [[2021-05-07]] I’m back to [[obsidian]] from [[foam]]. I no longer think it’s a deal breaker as pro-social companies might need to refrain but being fully open at all times to remain competitive in the market, and Obsidian’s business model (where they charge for optional features like sync and do not block community solutions in the same space) seems fair to me.
see [[defoam]] for a description of the migration process.