Yeah, I already understood that. I just thought the comment above was saying it already had ARM emulation, but it was bad or something. I just misunderstood what the above comment was saying.
Pretty sure Waydroid uses the x86 image of LineageOS, cus last time I used it (like a year or more ago) I had to get x86 version of APKs I wanted to install.
I moved an older relative to Mint and I regret it. Weird lagging and display server crashes sometimes, probably because of X11. Plus it's release cycle is very slow, so old packages. Ubuntu is far from my favorite distro, but at least it uses a DE with first class Wayland support.
You can use both through the browser, which is the safest way of doing things because the browser sandboxes the web apps, isolating them from your system. If you prefer an app for Messenger, look on Flathub, though I advise against it. The two apps I found for Messenger are Franz and Ferdium (a fork of Franz with more features).
Check out this website by the DivestOS creator for a privacy friendly online test (for many things, not just the 'tism): https://kairoscope.org/