Honestly only reason would be admin interface. If you need clients to manage the site than Gravs admin interface is horrible especialy if you have more pages -

Honestly only reason would be admin interface. If you need clients to manage the site than Gravs admin interface is horrible especialy if you have more pages - there are dropdowns everywhere so good luck if you have 500 pages. Also grav allow restroctions in admin so for example if you have /blog which contains blogposts you cannot say that /blog can only have pages of type blogpost - it shows every single type. Issues about this on github are ignored by Grav core devs on purpose. The reason for this is that they are company with bussiness plan and they are preparing their commercial "Admin pro" while they leave the basic interface just crippled. I would like open source too but fees are low and the devs are extremely open. Also kirby has much cleaner api, its much older and mature and the support is amazing. There are dedicated support people on their forums and you get response very quickly. From where you are coming from - i dont think its thing for you. Its aimed at noobs and rapid dev of presentational sites.