The top 3 conditions of a good singer are as follows:
i: The status of the musculus extrinsic laryngis is soft
ii: Abundant and thick vocal cord mucosa
iii: Taking breaths properly
One in a thousand people have this condition innately, and those kind of people progress quickly when singing.
Of course, you can acquire the above 3 conditions if you train.
Please don’t give up.
Note1: You can get a flexible musculus extrinsic laryngis by stretching. Making good vocal cord mucosa can be attained by improving blood circulation of the superior laryngeal artery and also by taking a hyaluronan, vitamin A and B2. Finally, learning how to take breaths properly can be achieved through training and practicing routine techniques with a competent vocal coach.
Note2: If I had to mention one more important condition to add to the above top 3 conditions, that would be a good ear for listening. Recognizing good music and having an accurate ear for it is very important. This is because in order to train and make improvements you need to be able to duplicate sounds from just hearing music or by reading sheet music. A good ear also assists in you own judgments in training and vocal performances.