Dua is not merely a means to get something from Allah — it is, in itself, one of the purest forms of worship (ibadah). When a person calls upon Allah, they are acknowledging their own limitation and Allah's total power, which is the essence of worship itself. Allah says, 'And your Lord says, "Call upon Me, I will respond to you." Indeed, those who are too arrogant to worship Me will enter Hell in humiliation' (40:60) — notice how directly He equates calling on Him with worshipping Him; refusing to ask Him is described as arrogance against worship, not simply a missed opportunity. This is part of why the Prophet described dua as the essence of worship: unlike physical acts of worship, dua can be done anywhere, anytime, in any state, and requires nothing but sincerity and turning the heart to Allah. It also explains why dua is never wasted, even when the specific request isn't granted exactly as asked — the act of turning to Allah in humble need is itself rewarded and pleasing to Him, regardless of the outcome.
Q&A · Dua & Dhikr
Is dua itself considered an act of worship?
References
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.