The person you replied to is right, the "security" of Linux might as well be nonexistent compared to macOS and especially iOS/Android. Even the developers of Secureblue (https://secureblue.dev/) state that despite their hardening and mitigations Linux still lags far behind macOS (and possibly Windows) security-wise. The only Linux derivative that has proper security is Android, and even better GrapheneOS.

https://privsec.dev/posts/linux/linux-insecurities/

https://madaidans-insecurities.github.io/linux.html

I also commented here on Linux phones, the same can apply to Linux as a desktop OS: https://news.ycombinator.com/item?id=46997397

Also on top of that Linux/Windows laptops also lack the hardware-backed security that Macs and to an extent some Chromebooks have.