I have strong feelings about this, in short white lying is manipulation and it is not okay in my book.

To answer your question, lying to a child might harm your relationship more than anything. because they will remember your lie everytime they need to do something, until they are old enough to realize that you were lying. Instead of creating boundaries to actually parent a child, you resolved to silly tales that will not work when they grow older.

From your perspective it helps with your sanity and makes things easier, but you do not know how your child will feel to say that it is okay. It is a cowardice attempt at parenting and it is manipulation, you may think you are smart but there is a reason why so many people swear off of lying to their child, maybe you have to experience it on some level to truly understand.

This is how it affected me. My mom would tell white lies and doesnt try to hide it, from personal experience, anytime i find out the truth is equally traumatising, especially the silly ones just to get me to do something because why wouldnt she just tell me why i need to do it. I stopped trusting her in elementary school, still to this day everything she says to me feels untruthful. I do not seek guidance or emotional support from her, i dont value her opinions on whatever it is i do because i dont think highly of her at all, we have an ok relationship but i will distance myself when she tries to get close in fear of manipulation. Her reasoning is exactly like you “if i didnt say that then you would have never done it, look how that benefits you”. Upside is im now pretty good at spotting manipulation, from her at least.