Form::getInstance (and similar getInstances) deprecation

[sintro]

As noted here

joomla-cms/libraries/src/Form/Form.php

Line 1839 in 793c4c2

* @deprecated 5.0 Use the FormFactory service from the container

Form::getInstance method will be deprecated in Joomla 5.0. Still, there are many places in Joomla 4 sources where this method (and many other gets with deprecation warnings) are used. With that, there is advice to use FormFactory service from the container. But Form::getInstance does many useful checks and preparations, which are not presented in FormFactory direct createForm method (which is suggested in depreation method as I assume).
So what is the point in this deprectation, if, first, Joomla own source still uses Form::getInstance (and not only this method with deprection warning), and second, there are not replacement methods with same functionality (with all that checks and cachings)?