I'm thinking of granting all players half-proficiency to their non-proficient saving throws so that there is still at least some scaling of all saves for all classes as they level beyond the occasional ASI put into a stat (The cool thing is that you can adjust this in DnDBeyond and have it automated). Has anyone tried this? I'm not sure if this would be "Yay, I save more often, I AM UNSTOPPABLE!" fun or "Looks like I saved again, not much challenge in this game." non-fun. Just wanting to get some feedback for anyone who has done this.
I tried this myself and there is no need. Mid to high level parties have a lot of save buff effects going on.
Firstly it further devalues dump stats (this is bad). Dump stats only ever really come into play when you're making a save based on that Stat. Watch your party Barbarian with the Int 8 cry when the Illithids and Intellect devourers come out to play.
Secondly, at mid to high level, there are a ton of buffs on Saves as it is.
Most common save Buffs are:
Bless
Bardic inspiration
Inspiration
Resilient
Nearby Paladins
Plus there are a lot of other niche class features that buff Saves (Divine Soul sorcerer from 1st level, War Wizard at will +4 to saves as a reaction, Monk proficiency in all saves + re-roll, Paladin aura, Bardic inspiration, Barbarian advantage on Str and Dex saves, Fighter Indomitable, Rogue Slippery mind etc etc).
You devalue those features a lot.
Also, in 5E failing a save isnt 'sit out the rest of this combat twiddling your thumbs'. Generally most effects allow a save every round, meaning it's at worst a round or two of suckage before the effect ends, so failing a save isnt a huge deal in most cases.
I still use +1/2 proficiency on Saves, but only for Champion Fighters as part of the Survivor feature (im a grognard and recall when Fighters used to have the best saves in the game; now they do again, and Champions can use the boost, plus it fits well with their 'static bonuses' thing).