I have an idea for an original campaign. In this world players start in an opressive kingdom where the system controls most of the things in peoples' lifes. One of the most important things for the king is total controll over ressurections. I figured out the best way to control such spells, for the king, would be a total ban on diamonds. This means that revivify is not worth just 300gp but needs a super rare component to cast, and getting it is a whole quest. I'm afraid this is kinda bad for players. Not that bad for a cleric with prepared casting, but as a divine soul sacrificing 1/5 of your total spells known for something that you will be able to cast once in a campaign feels bad.
#How bad is essentially banning resurrection spells
worn fjord
oak halo
just make it very apparent upfront before the game starts and maybe put in a replacement for revivify as far as something to prepare semi regularly if you feel the need
median kettle
You can just remove any spells you don't want to deal with. That's your purvue as the DM. Make sure you mention it up front and so that everyone understands that dead is dead. You should say if revivify or reincarnation are available. You can also say these spells are not ones that the PCs can learn, and are considered 9th level spells or something. Again, just make sure eveyone is on board with the type of game you're running. I'd say that restricting diamonds is probably not the route I'd take.
sacred breach
I'd figure out if you want to lose the gameplay impact of resurrection (aka, you want player stories to potentially be cut very short and players to likely be less willing to emotionally invest in their characters) or you mostly just want the narrative thing of evil empire controlling resurrection. If it's the later, you can tell PCs that as daring adventurers that get into wild situations, they can expect they might find some of the needed components, but that any resurrection will have to be kept hush-hush or cause problems.
median kettle
I'm not sure the only take away is that players will be less invested in their characters, although I suppose some may be. Also, I don't think it's required that some evil presence is suppressing resurrection either. It might just be that those spells are just not available or were never discovered. it might be that the "Death" agent in your world is greedy or strong enough to keep souls from being returned by mortals. The most important part is to be clear with your players about what is, and what is not available as early as possible.