Could sclera contacts work as regular contacts?

Sometimes: Scleral contact lenses are used in theatrical performances to produce for example completely blacked out eyes. These do not correct vision. Another type of scleral contact lens is used to treat visual problems caused by an irregular or badly damaged cornea. These often do correct vision when regular soft contacts can't.

Yes but why?: Regular contacts can be comfortable and give excellent vision. Scleral contacts are prescribed for special circumstances such as eye distortion, eye dryness, eye surface disease. They cost more, are harder to fit, and are generally a little less comfortable than standard lenses although this in part might be that they are used to compensate for disease.