I think the answer to your question depends on the workload you're planning to use Citus for. We find that users rely on Postgres for different use cases and Citus' benefits (and worst parts :)) vary across them.
Common use cases, ordered by popularity & benefits, include:
1. Multi-tenant database: Most B2B applications already have the notion of a tenant / customer built into their data model. Citus allows you to scale your transactional relational database to 100K+ tenants with minimal changes to your application -- and with all the benefits of Postgres.
2. Operational analytics: Citus enables ingesting large volumes of data and running analytical queries on that data in human real-time. Example applications include analytic dashboards with sub-second response times.
3. NoSQL++: As we increased Citus' feature set, we found that users started relying on it for workloads that have high read / write throughputs. We have a few "hidden" features in v6.1 that make Citus even more powerful here. That said, sometimes the open source community is way ahead of us on this. :)
4. Other: These include anything from distributed transactions to real-time notifications. Since we extend Postgres, if you're a power user and understand Citus' underlying primitives, sky's the limit. (We debated adding a section to our documentation for other workloads. We just couldn't agree if we wanted to name it Top Gun or Highway to the Danger Zone.)
Our goal in each release is to add new features that makes Citus stronger in use cases where it's already strong, as well as to listen in to our users & customers and look to expand into areas where we already see good adoption.