There is no native automatic table of contents in PowerPoint so creating a structured and convincing table of contents needs to be done manually.
You need to insert a slide at the beginning of your presentation and identify the different sections and their page numbers. You also need to make sure that the different elements are perfectly aligned and that your table of contents in PowerPoint is only one or two pages long.
If your page numbers or the names of your titles change, everything needs to be done again from scratch, meaning a significant loss of time and risk of mistakes!