Partitioning is not all that expensive. It is definitely worth testing for your specific workload. We use TimescaleDB, which relies heavily on postgres partitions, have a bit under 100 million rows in our active set (last 90 days), across 120 partitions (device*time), and it works nicely. Over 100 partitions is probably a bit many for this workload, but since it works OK we have not changed it.