“Any planet or house has to be hemmed (surrounded) between negative or malefic planets”
Each house indicates something and each planet indicates something.
For eg : Suppose your 4th house is under Paap Kartari yoga. The 4th house indicates home, family, mother, upbringing, relatives, basic education, vehicles and conveyances, peace, nourishment, confidence, righteous conduct, luxuries, homeland, real estate, land, home, and security.
When you see 2 malefic planets in the houses left and the right to it means, this house is under Paap Kartari yoga. You may have to be very careful in managing the matters of the 4th house. Same in the case of planets. Each planet indicates so many things like relationships, status, and career, wealth so and so. So, when this planet is hemmed or house is hemmed, the matters allotted to that house are getting squeezed to bring the best out of it. You should differentiate between the interpretations.
Life is not easy for anyone. All are struggling and finding a way to survive. Nature works in the parameter “survival of the fittest”. Those who fail, they fail ultimately. The truth is that there is no one with failures. Even when we look at the great men in epics who seems to hold a very next place to the Lord, they also have failed at some point in their lives. If you are looking for zero struggles in your birth chart, that is not going to happen.
This yoga or any yoga or you say dosha, gives you an idea about which area can be burdensome for you. Nothing more than that. If you see any house or planet under Paap Kartari Yoga, do an analysis on how life is treating you, related to the matters of that house and the planet, you will see that yes, the situation is little concerning. Not to get deeply worried, instead, find time to take some crucial decision about the current steps.
There is no point in repeating the same old strategies if you are getting the same old results.