Owing to these Navagraha doshas, persons face several obstacles & hindrances within their lifetime. So as to limit and negate the malefic doshas or malefic impact of these planets, we perform various Pujas & Yagnas. One more etymology indicates that valga means "to paralyze" and symbolizes the power of stambhana, https://www.youtube.com/shorts/5VeSyP9JRw0