My comparison is simply to show the standard laissez faire talking point of "oh, regulation exists just to protect incumbent market players" as bullshit: regulations exist to protect consumers from negligence and misbehaviour on the part of the companies.
The fact you think GDPR only applies to websites rather than the huge clusterfuck of personal data loss means you haven't understood the reason behind GDPR.
Equifax lost millions and millions of records and have so far faced no meaningful punishment from the UK regulators: as far as I can tell, they've so far made one brief statement on their website, and one tweet.
Major ISPs like TalkTalk lost millions of records (and ignored security researchers telling them about gaping security holes) and were given a slap on the wrist - £400,000 by the UK ICO. Mere pennies per user in fines; a drop in the bucket compared to their annual revenue. There is no economic interest to change their behaviour.
The negligence of these companies has led to millions of people having their personal and financial data stolen, having to keep eagle-eyed over bank statements and credit cards, having to worry that their transactions (or their travel bookings) might get flagged up as suspicious, that their credit rating gets eaten, and much else besides.
If a company you've entrusted your personal data with—not just your tweets or whatever, but sensitive personal data including health data, data about your religious affiliation, sexual orientation, etc. loses that data, as a UK citizen, you currently have no right to appeal the ICO failing to take action. GDPR/DPA2018 changes that balance.
Companies tell consumers "hey, trust us with your personal data". Consumers do in the false belief that there is some protection or basic responsibility taken. When they colossally fail to take the most basic steps to protect consumers from data loss, the status quo was this: nothing happens to them.