While Apple recently introduced the HomePod and iOS 11, former employees who worked on Siri told the Wall Street Journal the virtual assistant is lagging behind its competitors because of company concerns about user privacy.

Siri, which competes with Amazon Alexa and Google Home devices, is struggling to rise above the competition because of Apple’s culture, which prioritizes user privacy, making it hard to personalize and improve the product, former Siri team employees said.

Read: Amazon Sees Apple's Siri Talking With Alexa Virtual Assistant, Report Says

Amazon and Google assistants had an advantage over Siri because they had more data from their search engines they could use to train their virtual assistants and have less-restrictive privacy policies than Apple, the former employees said.

The Journal report said Apple protects user privacy by randomly tagging Siri searches and keeping the information tagged for a timeframe of six months, unlike its competitors Amazon and Google, which retain the data until ask for it to be discarded. That issue has delayed efforts to boost Siri because Apple "relinquished control of data before it could be used to gauge the impact of software tweaks," employees told the Journal

The former employees also said Siri's progress has been slowed because of Apple’s failure to set ambitious goals, shifting strategies and because vital team members left the company, with some joining Apple’s competitors.

Read: Do Not Disturb While Driving On iPhone, iOS 11 Revealed By Apple At WWDC

About a year after Apple founder Steve Jobs died, the company hired Amazon search executive Bill Stasior to take over Siri. However, some Siri team members said Stasior’s expertise in search, rather than speech or language, meant he didn’t appreciate the technology’s original goal, which was to expand beyond the iPhone to third-party apps, the report said. The iPhone maker began opening up Siri for developers in 2016, but by then it was too late. Siri co-founders Adam Cheyer and Dag Kittlaus departed the company and went on to start Viv Labs, and other team members followed. Viv Labs was then bought by Apple’s smartphone rival Samsung for about $215 million. The South Korean company is expected to launch its own virtual assistant Bixby, this month in the United States.

The Journal also reported detailed panic at Apple after Amazon introduced its Echo device at one of its events, realizing the online retailer's assistant had abilities Siri had not mastered yet.

The report comes after Apple revealed the HomePod at WWDC this week. The Siri-powered speaker, which is about 7 inches tall, will be priced at $349 and will be released in December. The gadget will work as a hybrid high-end music speaker and home assistant, controlling smart home devices with Apple’s HomeKit. Users will also be able to use the HomePod for basic reminders, to ask questions about the news and to control music and audio playback.

Apple also introduced improvements to Siri with the iOS 11 update, including live translation into five languages, learning a user’s interests and changing the voice from female to male.