Because that is precisely what separates consonants from vowels: consonants are sounds produced with a partial closure of the vocal tract. Depending on what type of closure the speaker does (in combination with other factors), a different consonant will be pronounced. And, as you have already seen, consonants can be analyzed according to several features: place of articulation, manner of articulation, aspiration etc.

Vowels, on the other hand, are pronounced with an open vocal tract. Therefore, by definition, it is not possible to apply those features to classify vowels. Other features, such as roundedness, must be used in this case. So, for example, it wouldn't make sense to speak of place of articulation for vowels. Similarly, since all vowels are voiced by definition, a "voiceless vowel" would be a contradiction in terms and so on.

Because that is precisely what separates consonants from vowels: consonants are sounds produced with a partial closure of the vocal tract. Depending on what type of closure the speaker does (in combination with other factors), a different consonant will be pronounced. And, as you have already seen, consonants can be analyzed according to several features: place of articulation, manner of articulation, aspiration etc.

Vowels, on the other hand, are pronounced with an open vocal tract. Therefore, by definition, it is not possible to apply those features to classify vowels. Other features, such as roundedness, must be used in this case. So, for example, it wouldn't make sense to speak of place of articulation for vowels.