Some parents behave very leniently with their children, but I believe this is not a good approach for parenting, and this has negative consequences on children as they grow up.
The permissive style of parenting is not a healthy approach used for raising children; instead, parents should teach their children discipline, and they should be bold enough to say no to the unnecessary tantrums thrown at them. Children are cant tell the difference between good and bad, so it becomes the sole responsibility of parents to stop their children from any bad activity. For example, if a child is adamant to buy an unaffordable costly toy, their parents should refrain from buying it. Admittedly, the first thing the parents should do is to explain the situation to their children, with love, but if they don't understand them, parents need to be strict for the betterment of their children.
The outcome of permissive parenting can be devastating. Firstly, children will become spoiled, adamant, and stubborn, meaning it will become their habit of demanding even more unrealistic things because subconsciously, they are aware that their parents are going to fulfill their demands no matter what. Secondly, they will never understand and value the importance of money as they have never faced any hardships in life; whatever they demand, they easily get from their parents. Finally, such children indulge themselves in bad habits of drinking and smoking. For example, in a recent survey, it was found that 88% of drug addicts have got this addiction because of excessive money and the leniency of their parents.
To conclude, parents should be friendly and good listeners to their children; however, they should be strict where required or otherwise, the consequences will be negative.