> unless you're saying that the best part of the original Doom games were the labyrinthine level design
Not the best part, but certainly one of the best parts. Doom and Doom 2 did labyrinths really well, much better than wolf3d (wolf's labyrinths were too samey and dull due to engine constraints) and I think better than nearly any game since. Games started foregoing labyrinths around when Half Life 1 came out (see also: Daggerfall vs Morrowind), I think because labyrinths filter plebs. But if you stick with Doom it'll teach you to have better spatial awareness that trivializes level learning in most other games. The new doom games particularly have linear level design very reminiscent of Half Life with some arena sections interspersed; they don't feel like Doom levels at all (except in very superficial ways, like "mars/hell themed".)
Such modern games lend themselves to navigating levels without maintaining a working knowledge of where you've been; at each instant your navigation choices may be informed by what you see on the screen right then without regard for what you've seen before. You can play Doom that way too, you'll get to the end eventually through brute force, but Doom does an excellent job of encouraging you to do better and develop your skill. If you remember where you are in relation to where you've already been, you can anticipate when a path is looping around to where you've already been before you actually round that corner. Maintaining orientation in this way, especially in a labyrinth, is a skill Doom excels at teaching. When you get good at it, such awareness of the level instills a sense of presence that just can't be conveyed any other way. Most modern games don't try to teach it; they expect that novice players won't be good at navigation and so, in the name of accessibility and mainstream appeal, refrain from challenging those players.
Many early first-person games (pre Wolfenstein 3D) were dungeon crawlers, not shooters, so the labyrinth design of early Id games reflects that heritage. Modern single player shooters have now very much abandoned this approach in favor of linear level design (Half-Life / Call if Duty approach), or they went straight into the "open world" direction (Farcry approach), which also doesn't feature dungeon/labyrinth levels. Closer in terms of non-linear level design is perhaps Metroid Prime (which recently got a remake), but it focuses more on environmental puzzles than on shooting.
There are probably indie games which are close to the original Doom formula. They often feature genres that have been neglected by big studios.
Gunplay and movement is not the essence of doom, you can't even jump or aim vertically. For me Doom is a monster blast fest on easy difficulty but becomes a strategy game on the hardest ones. A game that seems hard at first but when you find and develop the best approaches it becomes easy.
