Nowadays it is a must as a company to be involved with Big Data, because otherwise they don't count. With the Big Data they collect, they can learn all about their customers and improve their business processes. A few examples: Bol.com, Amazon, Cool Blue, Airbnb, Uber, Spotify, etc.
Big Data is basically collecting junk, because the companies collect all the data from customers and their own processes without thinking in advance what they want to do with it. The danger here is that they can very quickly violate the privacy of their customers with what they do with the collected data if they don't ask permision in advance.
Because big companies have collected a lot of data, they as a company can answer almost any data question for themselves and their customers if they wish and are able to. The complicated thing about Big Data is that the right questions has to be asked and the correct collection of data. Otherwise there will be nothing usefull in the data collected. Companies that apply this strategy well are Youtube, Facebook and X (formerly Twitter). So basically the social media channels. A good example is their advertisment. If I buy advertisment with one of the social media channels I will get the advertisment published with the right audience I need to buy my product. This is because they know their 'customers' = the social media users.
Now with the lockdown, many stores are forced to go online. They collect data from customers without thinking about whether they really need it. Many struggle with the idea of how to use this data to keep their customers happy. Stores where I see that things are getting better are: Bol.com and Amazon. This is because they keep a close eye on customer behavior on their website.
In this period of confusion of COVID-19 whether or not a lockdown, governments are mainly informed by people who interpret the data. In doing so, they combine many data sets into Big Data, but often forget the personal data, especially when it comes to medicines and personal health. Hopefully that will change with small data. Although I would not like to see all my data collected.