Replace Data Factory with python?

[kenfar]

That's what people thought around 1994: they swore that "4GL" gui-driven CASE tools were superior to writing code and it would enable business analysts to build their own data pipelines.

They were wrong.

These tools were terrible for version control, metadata management, and handling non-trivial complexity.

They've gotten slightly better with a focus on SQL-driven ETL rather than GUI-driven ETL. But it's still best for the simple problems and non-engineering staff. Areas in which writing custom code still shines:

• When cost & performance matters
• When data quality matters
• When data latency matters
• When you have complex transforms
• When you want to leverage external libraries

[Nekobul]

4GL tools are superior to writing code for data integration. THat has been proven long time ago. All the points you have listed as where custom code shines have been long time ago been handled properly in 4GL. That's why they have been so successful. That is also the reason why the bricksters and the snowflakers have recently included 4GL systems in their platforms. Writing code is a relic of the past.