Yahoo! has breaches and cyberattacks because they are an enormous service provider. Check the records, and you will not find any provider their size who has not suffered such breaches and cyberattacks. Yahoo! has been around a long time. Unfortunately alongside those technical issues, they've suffered from many bad business decisions and are now owned by a private equity firm. There's no use in suing anyone, but you should consider whether it's worth hanging on to your deprecated email addresses at all.