Where can I find high quality time series data?

I’ve been searching for a collection of time series databases, preferably open source and public, that includes data across different domains. The key requirement is that the data should be organized by time intervals (e.g., monthly, daily, hourly etc). Surprisingly, I haven’t been able to find a resource like this, which strikes me as odd because having access to high-quality, cross-domain time series data seems invaluable for training models capable of making accurate predictions.

Does anyone know if such a resource exists?

Additionally, I’m curious if there’s a demand for a service dedicated to fulfilling this need. Specifically, if there were a UI that allowed users to easily define a function that runs at regular intervals (e.g., calling an API, executing some logic), with the output being appended to a readily accessible time series database, would this be something the ML/Data science community would find useful?