When Suno is the better choice
Be clear about what you need. Suno's paid plans include tools AI Song Maker does not offer: stem separation, uploading audio, creating with your own voice, custom models and, on Premier, Suno Studio with MIDI and effects, according to Suno's pricing page. If you edit songs section by section or build on your own recordings, Suno does more.
AI Song Maker is simpler: describe, generate, download. It suits people who want finished songs from several models, pay as they go and never count downloads.