Debilitated planets are considered more vulnerable in comparison to say exalted planets. However, that only means that there is potential to do damage in the chart, it is not necessary that the results will be terrible. For bad results to happen, affliction is required. Affliction is defined as two or more than two malefic influences without a benefic aspect.

In my opinion, if one has to have afflictions, it is best to have them on debilitated planets rather than exalted planets. This is because the results for debilitated planets might be weaker. There, affliction might mean denial of results, and not intense suffering. On the other hand, the exalted planets’ affliction means that serious suffering is indicated in that area of life.

Problems caused by exaltation of planets: It is not what it looks
Also, when it comes to reading a horoscope in a practical way to give meaningful predictions, and not just theoretically, exaltation and debilitation are seen in a very different way. For example, an exalted Jupiter is considered to make a person very arrogant. Jupiter is the swa/Jeev karaka and it’s exaltation can give some problems in personality. Similarly, Lagna lord’s exaltation is often linked to a person’s inability to adjust in marriage. Since the Lagna becomes too strong, the 7th from it, the house of partnership weakens. If both Lagna and the 7th lord are exalted, this might result in a clash between two strong personalities in partnership. Similarly, a horoscope with 3-4 exalted planets is not considered good, as the person loses the drive to put in efforts in any endeavor and instead develops a personality around themselves.

Now, this does not mean the good results will not be there. A person with 3-4 exalted planets will never face instability in their life and always have someone around to take care of them. An exalted Jupiter will give excellent results for children and even the house which it lords.

Unexpected results of Debilitation: Mercury and Venus
Now, coming to two planets, which are considered better in debilitation, though selectively, are Venus and Mercury. Mercury’s results in a chart are unpredictable to some extent, as its result depend on the influence it is under. In its debilitation, it is in Jupiter, the guru’s sign, and its results are supposed to improve. Similarly, an exalted Venus is excellent for spiritual growth and learning, but for a person wanting materialistic success, a debilitated Venus is a much better choice. Venus is in a friend’s sign in debilitation, it does not do much damage, it is just the nature of Venus changes 360 degrees as it moves from exaltation to debilitation. Venus now starts giving results of the material world matters.

Why one planetray combination is irrelevant: How to read a horoscope
However, keeping aside all these combinations, the most important factor to understand a horoscope is the overall alignment of planets. An exalted Venus will give good results in a Jupiter-dominated chart. Here, Jupiter and Venus together drive the results of the horoscope, making the person go towards knowledge and spirituality, rather than materialism. However, consider an exalted Venus prominently placed in a chart, like in the 7th or 1st house, along with Rahu in the 1st house. Here, both these combinations will create a contradiction in the chart. While Rahu drives the person towards materialism, an exalted Venus will reduce the chances of the fulfillment of those desires. The result will be frustration and suffering for the person.