Huh? I've been using LUKS for FDE (with unencrypted /boot) way before 2015, and it's never been a problem. Debian has offered an option to set it up during installation, and it was 100% smooth sailing from there.
More recently, you can even set up GRUB to ask you for the passphrase, so even /boot is encrypted, you only need a tiny 2MB partition at the front to hold the bootloader.
Well I remember getting completely stuck at one part and the cause was my samsung SSD's funny behavior in the "locked" state.
I had to set some kind of kernel flag or something (sorry, it's been years) to get it to ignore the drive until I unlocked it, as there was some kind of tight-loop where it would just keep trying to connect infinitely and not progress/fail/timeout.
I've been meaning to get back into linux again but it's going to be on a pristine/new machine.
Well the work is in setting it up. Once it's working you just enter a password. I'm sure hardware FDE support in linux has come a long way since I last tried.
There shouldn't be that level of work required to set it up. The tools are lacking if it's not just a couple of commands or toggles to get a fully encrypted disk with a secure boot chain.
More recently, you can even set up GRUB to ask you for the passphrase, so even /boot is encrypted, you only need a tiny 2MB partition at the front to hold the bootloader.