Caty sits next to 4 phonetic neighbors — Katie, Catie, and Katy are the closest matches by sound. Most share Caty's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pure"
"from Denmark, Danish one"
"strong and studious"
"beautiful"
"singing, melodious"
"Blue; sapphire; sky-colored"
"Clear, famous"
"flowing one"
"Modern African-American invented name; possibly related to Tanisha ..."
"coined American name; likely from Keisha/Keziah (cassia tree)"
Similar sound: These names share phonetic patterns with Caty — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Caty.
Rhythm: Caty is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.