+1 on Kirby. It brought back fun in working on projects with CMS as a requirement. The cost for a license is easily justified when I calculate working hours and nuisances that would come with Wordpress.

For now I didn't find the comparably tiny plugin ecosystem to be a problem. It's well documented and lets me write missing functionality quickly.

My first encounter with it was because a wordpress project annoyed me so much I started to look around for alternatives. I took the project as a real-world example to take a look at Kirby and rebuild the site in an afternoon.