Qt Quick TableView performance issue when updating ContentY in onModelChanged

TableView should always show the last line by setting the ContentY.
When updating ContentY in onModelChanged, the view loads data for every single cell and is quite slow to display. The performance should be improved.

The behavior can be reproduced when populating the TableView from a custom model that provides 1 000 000 lines with 3 rows each but is also observed with more complex models.