LibreOffice Writer 7.1 dropped the To Page anchoring option when inserting an object in the document. Existing To Page anchored object > are preserved but not an option anymore for new objects.
That is not quite right. It has been not "dropped", but only hidden from "Anchor"-menu. You can still get the anchor type "To page" from the "Type" tab in the properties dialog (images and frames) or the "Position and Size" tab in the "Position and Size"-dialog (shapes).
And if you want to have it the same way in the context menu as in previous versions, you can customize the context menu. You need to make a submenu "Anchor" in e.g. the context menu of "Image", then select the new submenu in field "Target" and then add all the anchor types to it.
It was hidden, because you really need to know the impacts of "anchor to page", when you use it. But people try to use it to prevent images loosing position, but it is not designed for that purpose and the wrong anchor type for that.
An interesting source for object anchoring and positioning by Mike Kaganski may be used in our guides on anchoring:
And in this context, another important change: you can now specify as a default which anchor type is used when inserting an image. Tools > Options > Writer > Formatting Aids, section "Image".