"Worth it" is always subjective. At CRT, the princesses will cycle through one by one, to say hello and pose for photos (you'd need to take selfies if you wanted this as no 3rd party takes these photos, with the exception of a posed photo with Cinderella prior to your meal, which Photopass photographers will take.) None of this is required. We've been there & said hi, but skipped photos, & you're free to wave a princess on to skip your table. You can tell them you want to skip the photo with Cinderella as well.
Plenty of adults go solo to Disney, so you won't look weird for going to a character restaurant solo. I guarantee that all of the characters see that every day. They seem to enjoy meeting anyone who likes them, so if you are happy to meet the character, then show it. We're all allowed to be kids at Disney. I saw a group of jocks in their 20's once excited to meet the characters at 1900 Park Fare (Alice in Wonderland, Mary Poppins, Tigger, Pooh, etc.) and the characters seemed to genuinely enjoy that, too.
If I were going solo, I would enjoy character meals as they provide a bit of interaction. Also, watching the families around you interact with the characters is enjoyable people-watching during the meal. Besides the characters themselves, Cinderella's Castle is just a special place to dine. It's a castle, after all, with flags and picture windows in the dining room, right in the middle of the Magic Kingdom. Crystal Palace (where you meet Pooh & his buddies) is also a beautiful place to eat. If ambiance at a meal matters to you, I'd recommend them both.
Have fun and report back.