For some reason, the libxaa.so library is missing in the xorg-server package.
This breaks some older video card drivers.
The s3 driver is an example.
It does not support the AccelMethod option, instead seems to be hard-coded to use the XAA method.
The libxaa.so driver must have been removed from the xorg-server package some time since 2014, as you can see in this post: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=195810#c3
Could the libxaa.so driver please be put back into the xorg-server package?
XAA was removed upstream in 2012, see the git commit upstream here: https://gitlab.freedesktop.org/xorg/xserver/-/commit/e191e296e6e7861978ea4a0ae9aa7b780e52732b
There is not much we can do, as it is not part of the distribution any more.
If you have an issue with a specific driver, please check if there's a fix upstream that can be imported, and create a new PR for that driver.