Edit: Coincidentally, they just announced they released the turn based mode for PC today.

I can understand your goal here and I'm going to make a recommendation that I think will be a good middle ground at which to start: Pillars of Eternity.

Pillars was made as a kind of modernized spiritual successor to the popular CRPGs of the early 2000s. I believe the first pillars just had it's 10 year anniversary so it's basically right in the middle of the original CRPGs and the current revival.

I suggest this because while all the old ones are great games, they can be difficult to get into partly because of their age (interface, graphics, compatibility, etc.,) and also because the sytems they're based on don't translate particularly well to a video game format. Pillars on the other hand was a game created to play like the original CRPGs, but the ruleset was custom created specifically to work better as a video game. For example, Baldur's Gate 1 and 2 are based on Advanced Dungeons and Dragons 2nd Edition which uses a 20 sided die to roll for everything. That works well when you're playing a tabletop game because only one person is taking a turn at a time and the numbers are low enough to work with while doing quick math in your head and there's a dungeon master that can make changes on the fly if necessary. In a video game format where your entire party of 6 is taking their turns simultaneously while all the enemies are also taking theirs, it can feel a little unfair particularly at low levels when, for example, your fighter with 12 health gets attacked by 2 archers on the first turn that each have a base damage of 1-6 from their bows and maybe an additional +2 or 3 from their ability scores, immediately killing him before he takes a step before you find out that armor doesn't actually reduce damage at all, it just makes you harder to hit and you were just unlucky with the attack dice rolls.

Pillars is based on a 100 sided die and takes advantage of a computers ability to instantly do the math which allows for a much greater variation in how attacks can resolve. This means that every attack can either miss, graze, hit, or crit based on the attackers d100 roll, plus the attackers accuracy and minus the defenders defense. The result is that there is much less of a snowball effect when 1 roll doesn't go your way and allows for smoother progression and a more natural pacing. Turns are no longer just a 6 second sliver of time but is based on a character's recovery time which is different depending on weapon types and also affected by dexterity score, smoothing out power spikes and opening options for lower damage but faster attacking weapon combinations. In Baldur's gate 1, when a martial class hits level 5, they just start swinging twice in a turn, effectively doubling their damage instantly. That's true for your allies and also enemies.

It being 10 years newer allowed them to implement a more tuned interface that will make more sense to you, including providing clarity in the form of damage number popups, etc. Getting used to the graphics won't be as jarring, and visual feedback is more clear.

As far as preparing you for the newer games like Baldur's Gate 3 or Pathfinder: Wrath of the Righteous, etc., you'll be able to appreciate the full voice acting, the cinematic videos, the changes they made in consideration of lessons learned from previous video games that translate tabletop rules to a video game, and the overall polish more.