Rogue Trader is clearly in the same genre as Baldur's Gate 3. Gameplay is split between tactical combat, character development, and lots of dialogue. Thus it isn't a bad answer to the question what to play next, for those who got into the CRPG/TRPG genre with BG3. And where Rogue Trader is strong is in the world it presents; it might not be to everyone's liking, but the Warhammer 40K world is more original and interesting than the somewhat generic fantasy of the Forgotten Realms. Where Rogue Trader is weaker is that much of the exposition and dialogue is in the form of the written word, not even always with voiceover, and with the characters as still portraits or tiny on the isometric map, with zero motion-captured animation.

Baldur's Gate 3 uses the Dungeons & Dragons 5E pen & paper rules, with some minor modifications. Rogue Trader uses the Rogue Trader RPG rules, and I can't say with how many modifications, because this isn't exactly a very wide-spread RPG rules system. What I can say, is that it resembles a lot more Pathfinder than D&D, with the rules system being significantly more complex, involving more math, and being more suitable for people who like to min-max optimal builds. It is the sort of rules system that I don't like to play in the pen & paper form, because it is just too much work, and the administrative works easily gets in the way of playing the game. As a computer game that is less of an issue, because you don't have to manually track yourself for example the warrior's Sworn Enemy talent, which gives "+(10 + 2 x TGH bonus)% armour and +(2 + STR bonus) damage on melee attacks". You can do some fun combos and things in the computer game, without having to use a totally optimized build.

Baldur's Gate 3 has a relatively linear main story, with some freedom for side quests. Rogue Trader seems to have less freedom, at least for the first 20 hours that I played. Suspiciously in both my playthrough and the one playthrough I watched in parts on YouTube, you end chapter I of Rogue Trader exactly at the moment where you hit level 16 and can choose your second class. At least in BG3 there was more choice and variety how long you wanted to play act I before starting acting II.

In Rogue Trader in chapter 2, new game elements are introduced, like ship combat, colony management, or resource extraction. Unfortunately this doesn't make for a great game. It also adds more weight to the question of why you, as somebody powerful enough to rule over a star system, have to constantly go out with a small squad of not more than 6 people and engage in combat. At least the fact that your star ship is 2 km long and built like a cathedral results in there not being a silly weight limit to the loot you pick up, like in Starfield. I still don't know why for example the number of medkits I can buy is limited in view of this near unlimited wealth.

If you can live with the cruel world and the logical inconsistencies, and just take the game as good fun, there are many hours of enjoyment in Warhammer 40k: Rogue Trader. It definitely fits my "more than 1 hour of fun per $1 spent" criterion. And by playing on a more medium difficulty, I avoid having to work too hard to optimize my builds, just taking what looks like fun and getting away with it. Rogue Trader isn't a particularly hard game, but can get a bit annoying with the injuries and trauma system sometimes. I don't regret having picked this up, but I wouldn't necessarily recommend Rogue Trader to an audience as wide as Baldur's Gate 3.