Computer desk panels were all butt joints

Hi. I’ve just started watching the show on GBH and watched the one on making a computer desk by rehab’ing some metal cabinets. I’m an intermediate wood worker/hobbyist. I’ve noticed that most of the show’s work, when joining two or more larger planks of wood, it’s all done as a butt joint with glue (sometimes using the special finger technique). I’m curious why, especially with larger lengths and or widths, why some kind of biscuit or dowel isn’t used. Is it because the glues are so good it’s not needed or it’s too hard to get the surfaces to align – or using biscuits doesn’t add much strength?

Thanks,

Mike