to put 5 buttons on the same line using the anchor would be messy?
Depends what you want to happen with them when the layout is scaled to fit the phone screen.
If you space them out evenly, all anchored to the left, and
if for example the phone screen is 1.3 times larger than your layout, then all the positions and sizes are multiplied by 1.3, and your buttons will still be evenly spaced across the screen. Ditto with vertical alignments.
But if the aspect ratios of the phone and the layout are not the same, then things would begin not lining up on the right edge or bottom edge. I read a lot about how anchors are the answer, but my experience has been that they are only the answer if you have one or two things across the width or height of the layout, and there was a mention in the video above at 8:04 that alluded to the same limit.
The solution to that is Designer Scripting, per the above video from 9:42. That example is vertical rather than horizontal, but the same concepts apply.