I have the same feeling as you, but it has improved a little since v2.10.12, the breakpoint is triggered when the note list panel width is less than 324px, and I think it's better than before. But for me, I think below 300px will be better.
At this point, here's a suggestion:
/* add the below into your userchrome.css */
.search-bar ~ div {
display: none;
}
It will work without a problem if the updates do not add any elements between the search bar and those buttons. So, it's way better than using the random class if you want to hide it by custom css.
An option inside the joplin's settings would be great in order to be able to choose between the previous UI and the new one. I feel very inconfortable with the new one (I only use JOPLIN on computers). I really need to have a separate line for the search zone (like before) and not a "magic circus" zone !