He probado el formato como
['mobile-number', 'name', 'about'].includes(stages)Pero eso no parece funcionar.
if (stages.includes('mobile-number') || stages.includes('name') || stages.includes('about')) { array.push('about-you') }Estás buscando Array.prototype.some
stages.some(s => ['mobile-number', 'name', 'about'].includes(s)) Esta es la alternativa exacta de las stages.includes('mobile-number') || stages.includes('name') || stages.includes('about')