openSUSE also has a simple FDE setup. Just check a box and enter a passphrase during install. It’s not default, but it’s about as easy as possible to set up.

I can second Beelink here. I bought a Beelink SER5 for US$380 as a gaming computer for my kids. It’s an AMD Ryzen 7 5800H with a Vega GPU, 16G RAM and a 500GB SSD. It probably won’t work well with the latest graphics-intensive games, but it’s been great so far with a bunch of games my kids like.

That one worked so well that when I needed a new desktop computer for their schoolwork and similar, I got another Beelink, this time a Mini S12 for US$200. It’s an Intel N95 with 8G RAM and a 256G SSD. Works absolutely fantastically for its purpose.

Both are tiny and silent.