If ITA were sufficient, why would we be looking for fares at EF in the first place?

EF orders the results by base fares, which I find useful. Fare rules, routing rules, etc are available with one click. At ITA you'd need to build complete trips to see the rules.

Besides, I am talking about strengthening the capabilities of EF which is a paid service. ITA is a freebie which can be taken away anytime.

The only reason I mentioned ITA was to illustrate a syntax that, eg, allows you to ask about fares from 6 origins to 4 destinations through 3 possible connections, all in one query. At EF this would take 72 queries.