I'm using PowerPoint online to make a presentation where .pptx is required. It's annoying. A lot of features (video cropping, changing slide master title, ...)

I'm using PowerPoint online to make a presentation where .pptx is required. It's annoying. A lot of features (video cropping, changing slide master title, ...) do not work in the online version. I literally had to ask a colleague to edit the slidemaster title for me. Also, it's quite slow in loading pictures, videos.