Comment # 3 on bug 1224808 from Antonio Feijoo

(In reply to Frederic Crozat from comment #2)
> (In reply to Antonio Feijoo from comment #1)
> > By default, dracut gets this info from /proc/self/mountinfo. To use
> > /etc/fstab as the primary source, you must use the `--fstab` command line
> > option or the `use_fstab=yes` configuration option.
> 
> When I did the change initially, I changed fstab, regenerated initrd and 
> rebooted (so it is used) but system end-up with compress= and not
> compress=zstd:1 
> 
> Regenerating initrd on the rebooted system still give the same thing.

That's strange, I tested it before and it works for me:

> May 22 07:44:43 localhost dracut-cmdline[218]: Using kernel command line parameters: ... rootfstype=btrfs rootflags=ro,compress=zstd:1 ...

Do your have `use_fstab=yes` in any conf file under /etc/dracut.conf.d/?
Otherwise it will not work.