I bought the mobile version of Baldur's Gate last year. It was fun, worked fine and all but the screen is just too small for some areas. I have a Samsung S9 with a 5.8 inch screen. I gave up at Durlag's Tower. With all the traps and tiny areas to explore it just doesn't work. I'm getting a new phone later this year that will probably have a slightly bigger screen. Is it better with say a 6.4 inch screen?
I can elaborate and say that the problem is hitting what you want on the screen. If you want a character to stand next to a wall in a tight place it's almost inpossible to press on the place you want. You either hit the wall or too far away from where you want.
I think it's better to play on a tablet, laptop, or desktop. Bigger screen. Maybe also real keyboard/etc which won't occupy precious on-screen real estate just to control and interact with the game.
I don't think a phone with a bigger screen will make much difference. A bigger postage stamp is better than a smaller postage stamp, sure, but it's still a postage stamp. Still limited in what can be displayed, you'll still be squinting at tiny pixels, you'll still be frustrated by clicking on tiny pixels. You're basically fighting the interface on your phone, why do you expect things will get better after "upgrading" (rescaling) to the same interface on your next phone?
I've never played this mobile port so I don't know how good or bad it might be. But the original versions of these games (on PC) sometimes require some tricky mouse-clicking on hidden objects which might be impossible to emulate on a small touchscreen.
There might be apps which enhance the pinch-zoom or magnify-zoom features of your device UI in ways which can improve your experience with this game.