powerapps to update data source

Ive been watching tutorials on how to use powerapps within powerbi to update the data in the model.
Although this is really cool, there are a few things that have not been explained, i was hoping to clear up here:

- if the data is sourced from a database elsewhere, is it bad practice to update the powerbi data model as its now not consistent wtih the data source?

- is it possible to use power apps to update the source data set and refresh the model , instead of updating the data set directly?

Appreciate any adivse and expertise.