The main reason why was that it's a personal project and I wanted to do everything on my home server so that I wouldn't have to pay for cloud resources, and so that I could learn Postgres, TimescaleDB, and eventuallly PostGIS.

But as rabernat pointed out in his comment, pulling out a long time series from the cloud replica is also slow. And I know I eventually want to perform complex spatio-temporal queries, e.g. computing the 99% percentile of summer temperatures in Chile from 1940-1980.

I don't doubt that a cloud replica can be faster, but it's at odds with my budget of $0 haha.