I think #Amethyst has reached a level of sophistication where it can start asking for a fees - to support the devs ..
A simple model that I will pay for 
- Drafts - free
- Note - 50 sats 
- comment - 10 sats 
Or 
a pro model where I pay say 1000 sats per month for unlimited notes and comments .
It is important :
-  It helps dev ecosystem.  New clients' devs see a path to monetization. In a way , users are incentivised to try out new clients .. 
- If you ( as a user ) are willing to spend time on new clients - you invest your time to help testing / ideation . You get free #nostr but you know free is NOT an ultimate solution. Paying for software is a habit - a good one !
-  If software is free , perverted means to support dev are bound to percolate -  pesky ads  :-) are probably the least of your concerns ..
As for #apple nostr developers (read #Damus) .. if you are NOT charging for your software ( open source or not ) , you are probably culturally misaligned :-) .. you should move to Android / windows .. pun intended :-)  
PS - I don't use apple software - hardware is a different thing - love it !