Under 100GB; I'm sure vanilla Postgres would suit our needs too. However, adding TimescaleDB on top was not much of an investment and in exchange we got an interface for operations we do often, effortless continuous aggregation, near-constant time appends, and a native way to leave data mutable for a period of time before marking it immutable and compressing it.
The performance is a great feature but its also just an intuitive, familiar (pretty much just SQL) tool that makes life easier.
