For accessibility reasons, options for subtitles were removed, in order to standardise them across all Dreams. Sorry for any inconvenience. If you want more snazzy text you can use one of the other text gadgets depending on the use case. For accessibility, if you are doing subtitle/dialogue text, we advise that you still use the subtitle gadget and have them standardised to be accessible to all users. Also note the 'Always Show Subtitles' toggle. This means that your subtitle will show even if the user has subtitles off in the preferences. If you have no actual audio for your dialogue and the text is the only way to access it, you will want this option turned on.
For more information on making your games accessible check out: -