Sensory issues are a possibility, so is an underlying GI issue. Food refusal is very common with eosinophilic esophagitis and can be the only symptom, along with failure to thrive when it gets extreme. I've got one kid with each and it's no picnic. I'm afraid the idea that kids will eat when they get hungry is bullshit. Not eating solid food can lead to constipation which leads to a reduction in serotonin created in the intestinal tract which further reduces appetite. That train can go straight to failure to thrive land and it's not a fun trip. My son didn't eat a bite of solid food for five weeks last winter and it was anorexic snowball that just got worse and worse. No solid food increased his constipation, which further killed his appetite despite being on a large dose of Miralax daily.
The idea that some kids "just don't like eating" but are perfectly healthy is possible but unlikely. There are tons of physical issues that can cause a child to not eat, including anemia, food sensitivities, food allergies, autoimmune disease and sensory processing disorder. Refusal to eat solid food is a huge red flag for potentially serious problems -- oral motor problems, diseases like EE, sensory problems, etc.
I recommend a book called Food Chaining It discusses medical issues and sensory issues related to poor eating and how to increase your child's dietary repertoire.
