Why can't I swipe on YouTube videos?
Youtube videos are loading into iframes, which means, that they have no connection with the outside codes, they are like you would just open a new window in front of your website. There is one thing, that you could do, to have swipe over these videos, and that is to put layers over them. If you would put one layer in the left, one in the right, then you would be able to swipe your youtube slide in those places, and in the middle you would be able to make the video start and stop.
These layers would be on computers too, which might not be so good, so you could duplicate your slider first, and then choose which slider to load in what device. You can find the documentation for this in here: WordPress Joomla.