Ok fine, it's unrealistic, but, what mechanism should they use for a puzzle/platforming game? I mean I don't remember the old TR games much, but "ancient tomb with traps/puzzles" is as baked into the "archeology adventure" genre as they get. So, what should be used, to justify, even remotely, an ancient, pre...what, pre-iron age at least(?) culture, being advanced enough, to leave behind elaborate puzzles for you, the player, to jump around and solve? Unless you are literally going to use magic, or "ancient alien architects" (both of which are fairly classic as well), then the only thing that Joe Average is going to buy, if we're going for "realistic" is pullies and wheels.
So the devs are kind of in a lose/lose situation. If they go for "true realism" then you don't have any elaborate physics based, block shifting, puzzles for the player to play with. If they want to include that, they have to allow cultures, fictional or not, to have tech they didn't have access to at that time. Or like I said, just handwave and say "a shaman did it with tribal magic." But you know, that whole realism thing again.