Easier to code. You don’t need to worry about render interval and tick interval, as they’re both part of the game loop, resulting in a lot less code.
Once computers became too fast for this to be a practical approach, tick intervals became more common. That way, the Game would run at the same speed on any computer that was fast enough.
After a while, as graphics generally became more complex, it became apparent that the game logic was rarely what was taking up much of the calculation, so to avoid graphics slowing down the entire game, render intervals became a thing. Basically this allowed the game to run at normal speed, at then just let the graphics update as fast as they could if it couldn’t keep up.