True Strike is usually considered trap choice (for in-combat use, ie 99% of the time it should be useful) in pnp, as far as I know, for pretty much the reason you said -- it doesn't really do you any good. Even for weapon-focused builds like Eldritch Knight or your Ranger it's pretty much a self-countering choice. In fact I think it's mathematically negative (but please do not quote me on this I hate math and probabilitology makes my treeskull hurt) because I think you are trading two attacks (two possible hits) for getting two chances on one attack (can only result in one hit), meaning that the chance of one attack hitting is the same in either case, but if you don't cast True Strike you still have the possibility of both attacks hitting and thus doubling your damage potential.
+1 True Strike is usually a trap-choice (or for those familiar with MtG a "win-more" strat). It seems empowering but is usually out-performed by other abilities the party can use. Also with all the low-cost ways to get advantage in Baldur's Gate 3, it's hard to justify ever using True Strike.
I was surprised True Strike was put in the game, I thought it would have been omitted to prevent players from choosing it.
