The Photography Plan is a deeply discounted bundle for $10/month. If you got the same apps a la cart it would cost $63/month for Photoshop, Lightroom and Lightroom Classic. So you're getting a huge discount with the Photography Plan that is not indicative of "normal" pricing.
Add another app and pay the à la carte price. Add more than 2 apps and you're actually better off cancelling Photography Plan and switching to the ALL APPS bundle for $53/month which includes about 31 apps & services.
It's the same with my phone/Internet/Cable TV provider. They charge significantly less per item on a bundle than they do for à la carte. If you're like me you get the bundle to save money even though you don't use everything. I can't remember the last time I looked at the Disney Channel but it's in my TV package. If I tried to cancel Disney, it would end up costing me more than if I didn't.
Nancy O'Shea, Product User & Community Expert Alt-Web Design & Publishing ~ Web : Print : Graphics : Media
This just shows what an amazing bargain the photography plan is, not that the other apps need to be harmonized... the average user of the full $50/month suite uses 3-4 apps, and that is the price model.