That's the argument that the people trying to convince me that moving to AWS is better than Neo4j, they say it's worth not having to worry about backups and auto scaling. Luckily we chose to stay on Neo4j. I discount the "management" argument.
It's been my experience, getting back ups scheduled and running is one-time task. Once you have them being taken it's almost zero maintenance.
Auto-scaling also can be solved with just a little more DevOps work. With an enterprise license you can run a cluster and scale horizontally. EC2 instances also auto-scale. Adobe is running their Behance product on Neo4j and they have tens of thousands if not hundred of thousands of users all stored in a 3-node Neo4j cluster. This is where I'd ask how volatile is the traffic is your traffic to the database and are you're seeing huge fluctuations in your traffic patterns that a severless service is warranted.
Since my original post I started doing more research to find performance benchmarks and user experience. I couldn't find anyone who has had a positive experience using Neptune. I found people who did benchmarks and found that Neptune would even crash when their graph got to a certain size and the query tried to do more than N-number of recursive traversals. Unfortunately I don't have of those links saved of the performance but I read enough to convince me that no matter of "reduce work of backups" am I going to sacrifice actual query performance and have my application randomly crash. You'll easily eat up development time trying to debug random crashes than spending a day in configuring a backup schedule and EC2 autoscaling policies. Neptune has also only had 4 software releases, v18.104.22.168, v22.214.171.124, v126.96.36.199, v188.8.131.52 which doesn't show to me that AWS really cares about this DB technology. I think they found an open source engine that they could tweak and rebrand to check off the box that they have a graph DB but I don't think they're committed to their DB. I think they're probably waiting to see if graph DB rise in popularity before committing developer resources or they already know they can't compete with Neo4j so they're going to let their DB flounder for anyone who doesn't want to use it. Obviously that is speculation and opinion but it's worth consideration before choosing which technology your business is going to invest their strategic resources in using.
Neo4j has also since come out with their Aura service which takes care of the DBA argument that people use.
AWS Neptune is also a different graph storage model. It is a Triple Store vs Neo4j being a Label Property Graph. Say good-bye to property and labels that we all enjoy in Neo4j and be prepared for many many many more relationships to nodes to store the properties that used to be on a single node.
As far as query language Cypher, not only is the easier query language, it's also the foundation of GQL, the language that the W3C world committee for standards has adopted for Graph Databases. Which doesn't bode well for TinkerPop or Gremlin for staying around or for any developers trying to find help and support.
This ended up being longer of a post than what my intentions were but I spent a lot of time researching if AWS Neptune is worth consideration and my personal bias wasn't clouding my judgement. It's now been my experience that anyone who asks me why not AWS Neptune, they haven't actually used a graph database and they just read the marketing pitch from AWS that it's "zero DBA work". But they haven't actually considered what it means to use Neptune, they haven't used themselves, they haven't supported it in a production scenario, their opinion is completely from reading marketing material without any first-hand experience. I think Neo4j is strides ahead in performance, functionality (i.e. APOC library), AI/M&L, and a vibrant community to support you if you need help. Those trump backups and auto-scaling.