That’s a deliberate decision.
The button elements don’t scale that much when the interface adapts to different screen sizes. The button is cut in halve to give you a visual hint that there’s more on the right.
Your workaround might not work for all localizations, the app comes in many languages and some might have longer texts. If they would have made the margins smaller, it might not work for all languages. It seems they went for a set position for all buttons that kind of works to avoid individual adjustments for every localization. The app comes in 24 localizations!
But you might be in luck. On one of my devices, these UI elements look different. Still horizontal scrolling, but you might like it better. I don’t know if they are going to replace these elements or why am I seeing alternative buttons, but they do look better.