Might not seem like a big deal but it's the little things, together, that makes for a better experience when using the editor. Now it's been several times I have felt the intuitive need for such a feature when working in the editor, especially since we are now able to add sections everywhere. Sometimes merchants also add new custom coded sections, and it seems even apps can list content in here.
I've seen some stores with a pretty long list in there and clicking more than 3 times on "show more" seems inneficient and can get a little annoying even if it's not a big deal, just sharing my experience.
Also combine this with the fact that the Display Name of the section doesn't match the file name so it can be confusing to find the right section using ONLY display names.
Or when the display name is just confusing since UI has to boil everything down to 1 line of text and no descriptions or documentation.
A prime example of this is the Venture theme with its featured-products.liquid section BUT the section Display name is "Featured Collection".
I agree it's not so obvious to reduce a section with multiple features into 2 to 3 words.
With a search bar, maybe this could be solved with a new schema attribute to fit matching keywords for the section name. For instance, typing "reviews" would still generate "clients testimonials" section. Maybe it's a little far stretched. I'm not even sure a search bar would make a significant difference for most merchants, but sometimes you need to have a feature in front of you to wonder how you did without it before (like sections everywhere). A/B testing & monitoring this feature would give a proper answer whether it's useful or not.
I'm glad this feature has come to life. I used it today as if it always existed and just remembered it used to be a feature I requested. I have no idea whether this topic was influencial or not but I appreciate to see how much is done to improve the user experience!