From the POV of the large tech companies, it's mostly a matter of keeping the interviews short since the questions can be complicated yet fit in under an hour. The top companies are constantly growing, have ~3 year turnover and are flooded with applicants due to their name recognition. Why all the smaller ones copy this approach, I have no idea. The alternatives usually are just as unpalatable: pair programming, a long project, language triva questions, etc. So nothing changes.