I'll preface my response by saying everyone's experiences will vary, of course, so I am only addressing
mine as the OP (inspired by your post in the other thread LOL).
It is a new thing. Rings of Wizardry were incredibly rare (less than 1 in 2220 by the DMG when rolling randomly), as were the powerful RSW that Wizards (and others) could use. Of course in 1E, you
wanted those items, since casting in combat was incredibly risky (any hit or failed save ruined your spell and lost the slot). You couldn't move if there were somatic components (most of the better spells), so no DEX to AC or saves, etc. The DMG actually suggests casters resort to such items if at all possible due to this.
Sure, but then you are using a spell to conjure components for
other spells--a higher "magic tax" if you will.
Sure, they have, but again are rare in most cases! The Girdle of Many Pouches was my
favorite magic item for this very reason!
But, in AD&D, if you failed your save, your then made saves for all your equipment. Do you know what the save is for leather against a fireball? 13 or higher. So, if I failed my save against an opponent's fireball (assuming I lived, since with lower HP was in question...), I had a 60% chance my GoMP would be
destroyed!
Yes, the DM can make that decision--just as they could in 5E. But this was most definitely a problem in AD&D without the DM removing such items unless your DM ran a Monty Hall type game--in which case magic items were everywhere LOL!
IME (anyway) you weren't
meant to find ways around these problems, but you were always on the look out for them since they made the game easier for your character. A Bag of Holding was great to have, until you lost it (destroyed or stolen), at which time you lost everything in it.
I agree to a point, but in AD&D you either became more magical via magic items or spells, but only casters through spells, and then often temporary boosts until spells wore off (sure there were exceptions for really high level play).
Yes and no. I've discussed this at length now with current and former players after posting the OP. As I said there I never had issues with spells like Tiny Hut, Goodberry, or Teleport in AD&D. But in reviewing the two systems (and those spells) I've realized a big part of it is the automatic and "easy" nature of magic in 5E, as well as its prevalence in numerous non-caster classes.
Magic has become more powerful in many ways as well. Yes, I believe some of this was for a desire to simplify some elements, but I really don't know why. It wasn't complicated IMO and was a factor towards balancing casters with other classes (along with requiring more XP and lower HP for magic-users).
In 5E, there are too many magical races, classes, and subclass for me. Spells are too easy, too accommodating, etc.
I always used training costs, but it wasn't to keep PCs "poor". XP for gold was usually low (1 XP / 5 gp) unless the battle was hard (then it could be as high as 1 XP / 1 gp).
Really, lower levels were more about surviving to reach higher levels, at which point you
might have a magic item which made managing most resources a non-factor.
I don't think it was because such things were tedious (at least I know they weren't to me). Proper resource management and preparation for the adventure was a "mini-game" in some ways. If the game style had a lot of times when you were trekking into unknown reaches where food, water, etc. was hard to come by, spell slots had to be devoted to these things, and if anything happened to that spellcaster, the party could be in serious trouble!
Again, they haven't been doing it since the beginning in the fashion you describe IME. A lot of tables did choose to ignore such things because it wasn't important to them--their concern was more about combat or story points. To others it eventually became an after thought which would only occasionally become an issue ("Ok, you
had three weeks of rations and food in your backpack, but it was all destroyed in that
fireball so now your PC has no food or water...what will you do?"). And to some it remained a point of challenge on a more regular basis.