Every system has to decide where to draw the line on the prioritization of realism versus simplicity and speed of play. On one extreme you have the "one page RPG" system where you have exactly two stats and everything uses one or the other, rolled on a single D6. About two thirds of the way to the other extreme you get "Pathfinder has a rule for that," with some systems going into truly absurd levels of detailed minutia in ways that vary from being mote or less mechanically consistent to the old school D&D method of the designers pulling a random table out of their ass for every new thing they don't have a rule for yet and filling it out with whatever nonsense comes to mind in that moment.
I care less about realism than I do about having interesting decisions to make. I think it’s a really big challenge for game designers to make it fun and interesting for players — even highly skilled ones who love to strategize — without the game bogging down by having too many dice rolls/decisions to make.
What annoys me is when they don't have weapons have distinct special abilities, but they do have different damage dice. You end up with a situation where some weapons are just better than others, and if you think a greataxe fits your character better than a greatsword, you have to choose between dealing less damage, having a weapon that doesn't fit your character, or houseruling that weapons that don't have other differences deal the same damage and ignoring all those stats.
Playing PbtA games taught me that fictional positioning can have just as big an impact as mechanics. You can't wrap a mace around someone's ankle, but the chain of a flail...
I like THAC0 because it forces my brain to shift into an older style of play. With AAC I have a habit of subconsciously (and unfairly) comparing whatever game I'm in to 5e simply because of the mechanics. THAC0 really allows me to enjoy older editions and OSR games as their own thing.
It's funny, I don't think I would even understand the attack matrix reference, had I not just watched a yt series about Gamma World (and Metamorphosis Alpha).