There is really no need to completely remove the date, slide number or footer placeholders in the master of PPT to hide them on your slides.
If for some reason you do not want to show the date, slide number of footer on one or all slides you can simply do one of the following.
For the purpose of clarity I changed the colour, font size of the footers to make them more visible in the videos.
Hide the placeholders only on the title slide
Go to the Insert tab and click the Header and Footer button in the Text group.
Then check the box Don't show on title slide.
Click Apply (or Apply to all if you have several title slides).
Hide the placeholders only on the current slide
Select the slide you want to hide the placeholders on.
Go to the Insert tab and click the Header and Footer button in the Text group.
Then uncheck all the appropriate boxes.
Click Apply.
Hide the placeholders on all slides
Go to the Insert tab and click the Header and Footer button in the Text group.
Then uncheck all the appropriate boxes.
Click Apply to all.
Hide the placeholders on a particular layout in the master
Go to the View tab and click the Slide Master button.
Select the layout where you want to hide the placeholders.
In the Master layout group untick Footers. Leave the master.
If you do that in a presentation where those those placeholders are already in place you will see that they are still there. After you return to your slides it will seem that nothing has changed, but when you click the Reset slide button in the Slides group on the Home tab you will see the effect. The placeholders will be totally out of wack. That is what happens here in PPT 2019 anyway. Then you can delete them. Restoring them requires to recall the header and footer dialogue and reapply them.