I'm remembering EoB fondly.
WARNING: EOB and EOB2 spoilers following.
Sorry, I don't think you remember at all, the past is not glamorous as you remember it.
I replayed the entire EoB series last year (dropping at half of EoB3 because of boredom -- but EoB3 sucked, everybody knows it).
Plot ? EoB is the only game which has probably less plot than Tetris. There is a monster, go there, uh the entrance fell down, stuck. Let's not mention the endgame.
I find the magic system of Grimrock (which is very similar to the ones of Ultima Underworld or Arx btw) nice and much better than the D&D inherited systems imo which try to force a system meant to pen/paper in a crpg, only to find that in a dungeon crawler the memorize spell thing is utterly useless - if you need say a dispel magic (and you don't) you just memorize it once, rest, cast, replace with fireball, rest. You could basically memorize always the same spells for the entire game.
Let's not talk about the loot in EoB1, where +3 swords were easier to find than food. Where a cursed plate armor was still good enough to keep on (still better than the lower grade armor). Where you could put a plate armor in hand and it still dropped the armor class value (try it, use a plate armor in hand instead of a shield, you can go to -10 as easy as said).
EoB1 was so unbalanced that the entire purpose of the game was 1) find a wand of cone of cold or fireball 2) go to the kenku level, 3) win. You can play the game for 10 days or stay 1 hour on the kenku level and you would make the same amount of experience.
Also on EoB1, there were plenty of broken puzzles. You know, like the one which steals your items if you come from a direction, except that you are more than likely to come from the opposite one. Ditto for a chain in the spider level. And some puzzles which are still unsolved, in any walkthrough, 20 years later.
It had useless classes (Thief - can't remember of a door successfully picked in eob1, Paladin/Ranger - they were basically slower experiencing fighters) and went as far in its D&D madness to implement optional rules on maximum reachable level for given races (in Eob3) and non-resurrection for elves (all the games).
There were no reach weapon too and since range weapons weren't that great, I wonder how could you complete EoB1 without mages (besides how can you drop Xanathar down without mages - and you know what I mean - and without clerics ? one tactic requires a mage, the brute force tactic requires healing and much much power).
Puzzles: some of them were completely illogical. How the heck are you supposed to know that the platforms of a given room in EOB2 must be pressed in an X shape ? Arbitrarily and without any logic, in a level where you couldn't try and fail (you couldn't rest at all). That's pure cheese tactics. The puzzle in EOB2 where you would be stuck forever but not die (hope you did save in multiple slots!)?
About the settings: EOB2 was basically the monster manual dropped in a temple. Not that the mind flayers in EOB1 makes much more sense environmentally btw.
Do everyone a favor: replay EOB1 and 2. You'll see that in reality they are much worse than your memories tell.
(Disclaimer: EOB1 is one of my favorite games ever.)
For me being locked into a tunnelvision like a 1st person shooter but without any kind of aiming, blocking and so forth is not very tactical,
If you used a bit more tactic (like walking backwards, sideward, turning circles, having the enemy in the diagonal, etc) you would find you have plenty of time to select whichever spell you want from the mage.
Character development is either customizable or not.
Except that in all EOB games, it was both customizable, or not (using the premade party).
I also guess you don't like any other RPG in the world.. take Baldur's Gate II, what if you had invested all your proficiencies in, say, clubs ?
and onto options....4 and 3. 4 races and 3 classes....really??
Thank God! Just two weeks ago I started making a party for IWD2. It has like 9 kinds of clerics. 3 kinds of paladins. For like 12 races, many of which differ for small details, or have harsh level penalties you can't judge in a videogame or make no sense at all (what is the purpose of the half-elf ?). It has so many many many classes and feats, and skills, and so on it takes a Bachelor degree in character creation. And a walkthrough to check all the domain spells and see if a cleric of Lathander is better or worse than a Tempus one and how useful or useless is magic resistance to make being a drow an advantage or a penalty (in a low-magic world, it's useless). Talk about quantity over quality.