I feel like this thread is too focused on the arbitrary percentage in the lower left corner. I personally didn't pay much attention to it since it isn't explained anywhere how it's calculated. SOMETIMES you see modifiers next to it, like " ^ High Ground" but you don't always do, and most of the time I have very little idea why my hit chance is only 50% while I'm standing in a well lit room next to an Ogre the size of a barn door.
The most likely reason for me missing (or more accurately "not doing damage") are bad dice rolls. And attack rolls in BG3 are horrendously bad in my own humble experience. I've parsed my most recent run through the goblin camp and part of the Underdark and took 100 rolls. I'm talking raw attack dice rolls here, just a D20 roll before modification. Character was a Dwarf Fighter using a 2-handed weapon. At least half of these rolls were made with advantage. The average initial roll was 6.32.
It doesn't only FEEL bad at this point, it just is.
Lae'zel as an Eldritch Knight doesn't have any similar problems.
My inspiration to do this parse was a guy in a neighboring forum that measured 50 rolls at 6.35 average, which I already thought was quite low.
I seriously hope that Larian is also taking a look at roll averages in their telemetry and sort it by class, stats, weapon used, whatever it takes, because something is just off here and the number of posts about this topic tells me that players feel it.