This is incorrect. TikTok is actually a direct descendant of Musical.ly which Bytedance bought and rebranded, and was in competition with Vine.
TikTok is an international version of Douyin, which was released in the Chinese market in September 2016.[10] It launched in 2017 for iOS and Android in most markets outside of mainland China; however, it became available worldwide only after merging with another Chinese social media service, Musical.ly, on 2 August 2018.
From the links above Vine was already dying if not completely dead before TikTok was ascendent.