That doesn't answer my question as to why you say 'But we don't see sediments being laid down today on the scale they have been there
Thanks for watching the video, and sorry for the delay in replying. I don't fully understand the way they were applying Walther's law to deep sea sediments, so will read a bit more about it. And I didn't think the logic was very sound when they suggest that 'layers' traverse numerous 'banks'. The flume tank experiments suggested that for every three or four strata there are lots of layers deposited at an angle in a lateral direction, when you pour a mixture of coarse and fine sand grains into fast flowing water.
Still, it showed that if there were continuous transgressions and regressions of the sea over the land during a worldwide flood, caused by tidal movement of the water, then the different sediments could be brought to the same basin in succession and laid down in strata by currents.
What I mean about not seeing the processes in operation today that laid down the sediments of the Colorado plateau, through which the grand canyon was cut, is that the quantity of sediment is too great to have been transported by the usual methods (rivers, wind etc). The Coconino Sandstone, for example, is estimated at 10,000 cubic miles of sand. If that had been laid down over millions of years, why were no other types of sediment laid down among the sandstone strata, and how was it transported?