Are Greater Noida infra timelines just builder marketing?

Honestly, I'm feeling so frustrated with this whole property buying process. I booked a 2BHK in Sector 52, thinking the Aqua Line extension would be done soon. But ab lag raha hai completion dates bas marketing hype hain. Jewar Airport ka bhi same scene hai, construction kitna slow hai. Builders like Mahagun promise so much based on these infra projects. Kya ye infra projects actually on time complete hote hain? Ya sirf paperwork pe hi rehte hain? My EMI chal rahi hai, aur possession ka pata nahi. Anyone else faced builder delays due to infrastructure promises?