Yes, I know it seems daunting at first, I thought so too. But these are only the things visible on the surface. Doctors have like 10 times more names to memorize lol
And as I have to give feedback to the artists I oversee in my job, these names make it much easier and quicker to communicate exactly what I mean.
Once you see the logic behind them, they become easier. For instance, lateral which means side, lateralis is the muscle to the outside - while medialis sounds like median strip, and so it's logical that it means "towards the center line". Biceps means 2 heads, and so on. But for the bigger more common ones, yeah we do tend to just say pecs, delts, lats and traps. :)