Subtitles serve a lot of different purposes in our media. They can be an aid for people with hearing deficiencies, they can help us understand foreign languages without the need for dubbing and they can even be used when we need to mute audio and be kind to the other people in our homes. I may not personally use them in English language games, but I'd never call for them to be removed from a title. For some odd reason, the Spyro Reignited Trilogy doesn't feature subtitles during certain periods of its duration.
GamePitt noted this in an article a few days ago. Subtitles are present when talking to NPCs in the game world, but are completely absent in all of the pre-rendered cutscenes. While the original Spyro didn't use pre-rendered cutscenes for its story, Reignited Trilogy does and there can be some crucial information missing for players with impaired or no hearing.
GamePitt reached out to Activision and received the following statement:
When Toys For Bob set out to make an awesome game collection, there were certain decisions that needed to be made throughout the process. The team remained committed to keep the integrity and legacy of Spyro that fans remembered intact. The game was built from the ground up using a new engine for the team (Unreal 4), and was localized in languages that had not previously been attempted by the studio. While there's no industry standard for subtitles, the studio and Activision care about the fans' experience especially with respect to accessibility for people with different abilities, and will evaluate going forward.
That doesn't outright dismiss the possibility of subtitles coming to Spyro, but it certainly sounds like Activision has no interest in adding them. I really don't understand why they would be left out, especially if localization teams drafted up scripts for different languages. Whatever the case, if enough people complain about this, we could see the feature come in the future.