There is no Schengen wide database for entry and exit records. Your stay in the Schengen area is tracked only based on the entry and exit stamps in your passport. Italian authorities may likely keep an electronic record of your entry, but if you for example would leave the Schengen area from a different country, the immigration authorities in the other country would not have access to the Italian record.
That means, that 'smart gates' can currently only do a part of the required immigration check. They can verify that your face matches the biometric data stored in the passport and check the relevant databases for entry bans or similar issues, which itself will save human resources, but they can not give you the required stamps and they can not check if you have overstayed.
A new database, the so called Schengen Entry-Exit-System, is currently under development and is scheduled to go into operation some time next year. With this system, entry and exit records will be stored electronically in one register for the entire Schengen area and passport stamps will be obsolete. Available 'smart gates' will then be able to perform the entire immigration check without human intervention.