No amount of Linux hardening will get a system even close to an M-chip Mac. Software insecurities aside, desktop Linux OS systems have almost none of the hardware-backed security benefits that Macs do.
I don't think Apple is particularly any more secure against the US government than Intel is with supply chain vulnerabilities but I have nothing to back that up with aside from vibes.
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.
https://news.ycombinator.com/item?id=48448345 // When people escalate privileges on MacOS it's news, when they do it on Linux it's Tuesday (you might think the recent spate of privesc vulns on Linux was unusual but that is totally normal). I say this as someone who works on Linux security every day (I am a kernel developer) and uses Linux on every computer I have, both at work and at home, BTW. I am not a Linux hater or Apple fanboy by any means.
https://news.ycombinator.com/item?id=48444187 // I am just talking about the pure tech fact that GNU/Linux desktops do not have any meaningful intra-host security boundaries.
https://news.ycombinator.com/item?id=48059250 // To convince me Linux is full of kernel LPE bugs, can you share some of the bugs? [answered by the kernel dev]
I also have some cites of comments on Linux by the founder of GrapheneOS I could dig up.