It’s ultimately up to your threat model and values. MacOS seems to offer some security features that desktop Linux may be missing. I think it ultimately comes down to how much you trust Apple and the legal jurisdictions they may be subservient to, as well as whether or not your threat model necessitates that you take action to attempt to protect yourself from said entities to some degree or other.
If you find those entities to be trustworthy and non-threatening to you, then I suppose it would make sense to stick with Mac, strictly from a privacy and security perspective. Though I’d argue there are more factors at play when it comes to which devices and software people should use, such as how well they respect freedom and right to repair, among other things. But that’s kind of off-topic for this forum.
You might’ve noticed that Privacy Guides does have a soft recommendation for Kicksecure, a Debian-based distribution. But you also mentioned earlier that you’re not comfortable with using workarounds to getting official builds of applications, presumably because you’re unable or unwilling to use things like Toolbox which come with Fedora Atomic Desktops. If that’s the case, Kicksecure is definitely not for you.
I started a discussion not too long ago about having to use Debian-based distributions as an alternative to Fedora with one of the reasons being the lack of official RPM or Flatpak application builds. To save yourself some time from reading the whole thread, you can just read the summary of the conclusion I came to about Ubuntu. The short version is that Ubuntu (as well as other “just works” Debian-based distributions) probably isn’t as good as something like Fedora, but if Fedora doesn’t work for you, the latest version of Ubuntu is probably the next best thing. (Though @sha123 recommends the latest version of Ubuntu Pro instead, which I believe is only available for LTS… so I’m not quite sure which would be preferable.)
The reason I don’t recommend other Debian-based distributions is because they are either too difficult to use (such as Kicksecure) or not as secure (such as Pop!_OS, Linux Mint, etc) as most of them typically use X11, are further away from upstream, and are further behind in updates compared to the latest Ubuntu release. That being said, when distributions like Pop!_OS switch to Wayland, the potential security benefits of Ubuntu over their derivatives will shrink and those distributions can become more appealing alternatives. I’m not sure if I could ever recommend Linux Mint because of their terrible security track record, but if enough time passes without further incidents, maybe they won’t be so bad compared to Ubuntu (once they switch to Wayland, of course).