Bless. Which other spells are you thinking of?not really. That was just one example. Several spells also increase saving throws. Many of them low level spells most classes can get
It's true that low level characters had much worse saves. It sucks to lose your character. Now, save are not as brutal at low level but they can still be brutal and they continue to be brutal at higher levels. It doen't take instant death to want to avoid not instant death but gonna die anyway effects.This is not true at all. Low level PCs (even level 1) routinely encountered poisonous traps and venomous creatures like centipedes and spiders that all resulted in your PC death if you failed the save. Also green slimes, rot grubs, and carrion crawlers were also a common threat, and they wrecked you with haste. Rust monsters churned through you armor and weapons way faster than 5e. Ghouls took you out (unless you were an elf) and were faced at low levels.
And 1e did have a scaling system of sorts in the form of saving throw bonuses or penalties. Many creatures gave one or the other depending on it's hit dice. However, in almost all cases, failure was death (or some form of it). PCs faces such perils from level 1 all the way up to name level and higher. Saying it didn't exist until the saves improved is just flat out wrong.
That "scaling system" of sorts is not scaling. It's buffing and debuffing,
And now when that save is failed there's suddenly a clock to race, and no guarantees on what happens in the meantime or after that period expires. Just because that save is easier at lower levels or there's 24 hours to revert doesn't change that a person isn't going to want to get hit or give guarantees over that 24 hours.Let me give an example.
In AD&D, if you faced a creature that "their touch will turn flesh to stone (save vs stone or be petrified.)", you would do what you could to avoid that at all costs.
In 5e, that same creature is:
"dc 11 constitution saving throw against being magically petrified On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified for 24 hours"
Your planning on the encounter will be much different. Worst case scenario, you're only petrified for 24 hours, and that's after 2 failed saves at an easy DC. Worst case with AD&D, if you fail once you're toast. Permanently.
It does give the opportunity to save that character my actions other than casting flesh to stone.