My understanding is that graph databases came first and relational databases replaced them because they provided a reliable methodology to understand and accele

My understanding is that graph databases came first and relational databases replaced them because they provided a reliable methodology to understand and accelerate nearly any new access pattern without reshaping data (joins and indexes, of course). The new graph DB rhetoric does not address what changed to make the previously-fatal flaw no longer fatal. 10 years ago, I bought into the mongo hype, jumped before it was ready (ACID? Transactions? With our new philosophy you don't need any of those silly things!) and wound up cracking my head on the bottom of that particular swimming pool. I'm not keen to repeat that mistake, so this time I want to understand before I jump.