Agree completely. Fiduciaries can obtain personal liability (E&O) coverage for their breaches and mistakes, to cover their personal liability to the plan, but that is different from ERISA plan bond that protects the plan from dishonesty among those who handle assets (but not the identity thieves who dupe them).
Cybersecurity is a huge issue and scammers have been attacking retirement plan accounts because the oversight and diligence is typically not up to the level seen at banks and credit cards, and perpetrated frauds can often go undetected for a much longer time because many participants do not regularly look at their accounts. I know RKs, including our firm, are banding together and sharing best practices and other important information on attempted hacks to safeguard our industry and our clients' retirements.
Personally, as someone who has been paranoid about security and identity theft for a while, I look at bank accounts, brokerage accounts, IRA, 401(k) almost every single day. My wife thinks it's to keep tabs on her spending - but I assure her it's not (well, maybe just a little).