Why?

It is because I did some checking and the Fluid package does the templating syntax differently, like {{% stuff here %}}'s instead of {{~ stuff here ~}}, etc.

Also if ends with endif and not end; same for for, etc.

But why should we update the templates?

Because the GitHub action that uses Scriban can see a performance increase and less memory allocations by migrating to Fluid instead. Also soon it will have Trimming support and AoT as well allowing for single file exe's or Ahead of Time Compilations which would also improve performance as well.

sebastienros/fluid#935
I also left a comment on that PR as well, but I filed the issue here as I think this would be the better dependency for package vpm repos.