I suppose one can use this to manipulate others.

Look at it from the perspective of what is of more value to the recipient. I can appreciate an improvisational compliment. But I will value and remember a well thought out, specific and narrow compliment. It signals that something I did/said/produced impacted you in a positive way. It also tells me exactly what it was that worked so well. That is valuable information. It’s the kind of compliment I would remember for a long time.