Dragons before Dragonlance?

It's worth noting that Good vs Evil is the defining element of DragonLance as a setting. It's one of three setting rules of note in the AD&D DL hardcover.
It even goes to tracking good vs evil acts on a track.
Another is the Level 18 limit. At making the level 19 required XPT, one gains a choice - leave Krynn (to become one of the gods, eventually), or stop gaining XP, and stay 18th level, 1 shy of 19th.
The third is the moons effects on Magic.

(There are also the different spell lists for the three colleges, and the knight classes. And Tinker Gnomes. The higher knight grades are, functionally, prestige classes.)

If you drop the good vs evil aspect, and the partnering with Dragons, you drop what makes DL unique as a D&D setting. Note that the dragon-riders are fully partners with their mounts, not servants of, nor masters of, their mounts... at least in the good side. On the evil side, the dominance games determine who's the toff and who's the boss.




There are a few present in Le Morte d'Artur... I can't get to my copy to give chapter numbers.
Wizard of Earthsea is also a great series, but dragons are only slightly important until the third novel. The first three are good reads; the fourth, well, Sparrowhawk is a broken man... the 5th is decent; the short stories are decent.

Note that the AD&D MM is also a good source for pre-DragonLance, and is the only source besides Pern I've read to link color to capabilities.

Speaking of which...
Pern. It's a very different take on Dragons, and anything but Sword and Sorcery (being really Duty and Politics focused, and technically Sci-Fi, a point that becomes important in both of the origination trilogies... Tho' like good S&S, it's quick wittedness which wins the day, not brute force.

Dragon Riders Trilogy

• Dragonflight, (1968, portions published in 1967)
• Dragonquest (1970)
• The White Dragon (1978)

Harper Hall Trillogy

• Dragonsong (1976)
• Dragonsinger (1977)
• Dragondrums (1979)

Either is an excellent introduction to the Pern setting. 

Do note that it's late Medieval/early Renaissance surviving technology, and only very limited psionics. (There are basically three psionic abilities: the ability to telepathically communicate with one's bonded dragon, the ability to talk with all dragonkind {including the Watchwehrs and fire lizards}, the ability to teleport - and that's dragons and firelizards only. A certain subset of the bond with a linked dragon is to be able to pickture a place to have it teleport to.)

I can't be certain, but I suspect that Pern had some influence on DragonLance.

Funny, but I didn't enounter the sandbox until 1985 with Twilight:2000. Seriously. No one I new in the early 80's was doing sandboxes, either. Mid 80's, I heard from schoolmates about their sandbox games, but wasn't in their games.
Every adventure I played was very much either "Go clear dungeon X" with the travel being merely a means of spending and/or gaining resources, or "Go to X, do Y, come back to A, get paid."
Even the supposedly less linear modules we had, such as G1-3, were treated as showing up on the hill outside in cutscene fashion, then infiltrating.

I only ever bought a handful of D&D/AD&D adventures before 3E: G1-3 Against the Giants, D1-2 Drow, D3 Vault of the Drow, EX1 Dungeonland, S1 Tomb of Horrors, S2 White Plume Mountain. I was given Q1 Queen of the Demonweb Pits and I-6 Ravenloft. I "inherited" a bunch of 2E stuff, most of which I never read, save the GDQ-1 Queen of Spiders. I didn't get the DL modules until the late 1990s... in the DL Classics volume, and then I ran that in DL5A.

I started running D&D with Moldvay, in 1981. I'd been playing a month or two. The overland was, well... totally «bleep»ing absent from play in my early campaigns... because I didn't (and couldn't, due to release date) get Cook Expert until the following summer. ANd when using it, the overland was just a "how bad off are you when you arrive at the mission location" mode, rather than a major part of play.

Until I was running T2K 1E, I'd never just let players go and do. It just hadn't been part of Traveller nor D&D for me. Most of my friends hadn't experienced it either. Keep in mind that what was done in the 70's and early 80's wasn't always learned by word of mouth nor playing with experienced players - a lot was, "This looks interesting, let's get it" at the game store, followed by doing whatever style of play they grasped from the rules, and that came in several major strains - for some, it was a pure tactical wargame; for others, more of a mission-based game with some story; others still, Sandbox; and others still, a press your luck dungeon of the week with literally nothing outside the dungeons.

I tended to the latter in D&D until the 90's. Not just because that's all that was covered in Moldvay, but also because that's how Andrew ran the game. And what little I heard of Tod's game was much the same, tho' I was hearing about that from his little sister... I'll note that when he & I became friends, a almost a decade later, he confirmed he had been playing mission-oriented as well in the early 80's, but had migrated to a more varied style.

TLDR: Sandbox was NOT the only old-school play-style.

Fafnir
St. George and the Dragon
Lindworm