You’re not being careless at all. Considering how you actually use the software, your risk is quite low. They're likely reacting because QuickBooks Desktop 2019 was discontinued in 2022, meaning Intuit no longer provides security updates for that version.
When software is no longer updated, it leaves unpatched security gaps that malware can exploit. For instance, if you happen to click a bad link in an email or visit a compromised website, that malware could find a way in and access your data.
Fortunately, your situation isn't as bad as it sounds. Your strong security habits and limited usage keep your risk pretty low. Plus, since you don’t link QuickBooks to your bank accounts, a hacker couldn't use the software to get directly into your funds.
Your best line of defense is keeping your operating system up to date, which helps block malware from getting onto your computer in the first place. If you want to keep using the 2019 version safely, just make sure you're backing up your files regularly to protect your business data.
I also recommend reviewing the Intuit Account Security Checklist for more tips on protecting your information.
Please feel free to revisit this thread if you have any additional questions.
