Closer to pre-Bethesda Fallout games, in terms of tactics. It uses D&D rules, and every CRPG translation of those rules has fallen from the AD&D Gold Box series tree. This one has chosen to take a step backwards in time towards the Gold Box series (and the tabletop rules) with sequential, turn-based combat rather than the 'real-time with a pause option' of titles between then and now. Dragon Age is probably the closest thing to it you're likely to have played, if that's your RPG background. That one doesn't use actual D&D rules, but it fell from the same tree.
You have a lot more customization options in these games than you would in Fallout, and Larian has made an effort to have those options affect the story in substantive ways. 'Nuke everything with AoE magic until dead' isn't necessarily optimal, but I have yet to see anything in over thirty years where it doesn't work for the tough fights, if your tactical positioning is sound. It looks like Larian has countered this (the offensive spellcaster power spike at level 5 is both a classic problem and a hallmark of the rule system) by drawing out the low-level player experience.
TL;DR: It presents a ton of much higher quality content than, say, Elden Ring if you're into this sort of thing. It offers a multiplayer option, but many people prefer to play with NPCs filling those party slots to experience as much of those stories as possible, the way you would in a Final Fantasy game.