I actually did mean 3.5.

I've played a ton of 3.5, 4e, and 5e and I've never seen a day with 8 encounters in any system.
They're certainly not common, the impetus to rest is extreme, especially at low levels.
My first 4e group actually pulled a 8 encounter day, in the freak'n Keep on the Shadowfell, which got brutal. Action Points from milestones got us through it. Pre-E, Action Points, Item Dailies, and, at paragon, items that unlocked better dailies if you hit a milestone, all mitigated against that impetus to rest prematurely. But that only went so far - I've run plenty of longer days, for various reasons, but usually with some story element precluding rests. What really helped 4e hold together with shorter days was class balance, that and short rests (hey, original topic) after every encounter meant that, while they're was still an attrition game going on, it didn't readily turn into a death spiral.
Any other edition, yes, if you could possibly get spells back, you did, because it was just foolish not to. They're far too powerful/important a resource to ignore.
1e AD&D also tended towards shorter days. At low level, in particular, you could only handle so many fights before you ran out of spells and hp, and someone was going to die - or worse, drop to 'deaths door' and take a week to recover (new characters were instantaneous!)
I think the "short rest problem" that 5e was trying to 'fix' (the problem being that you were pretty likely to start every encounter at full hp, rather than start death-spiraling) was actually introduced by 3.0 and the infamous Wand of Cure Light Wounds.

I also don't think it was a problem, at all, in the pacing or challenge sense. The real problem was that 3e Clerics were given a lot of spells/day with the expectation they'd be diverted to healing, and with the WoCLW tactic, they weren't, which awakened CoDzilla like an above-ground nuclear test.
