The number of reactions doesn't always do that. I have about 13 reactions and they are basically intended for people to voice their opinions. I've had others but I've kept the ones that work.
I made the default reaction something that isn't really a reaction so that people actually took advantage of the other reactions. This is the "I read this" reaction that the point is that its not positive, negative or even really feedback which is how I use my reactions. However, none of my reactions provide negative reputation and the only "negative" one provides no reputation at all.
Going left to right:
Like
Agree
Disagree
Yeah
Love
Thanks
You're welcome
Great Idea
Cheers
LOL
Preach it
Cringe
I read this
On mobile this sort of sucks in some areas more than others but I've made it work. That said I'd say that some are lesser used (like Great idea and Disagree) but I wouldn't remove them because they all have their place within my community to be helpful. (Great idea is really useful in my Brainstorming and Ideas section for example and Disagree is useful for my conversations sections).
Would I like a little more modular use of it it? Maybe. I sometimes think it would be good to remove disagree from sections that it doesn't quite fit like Brainstorming and ideas or looking for help sections. Agree should probably really only in the same sections as Disagree because "great idea" and "thanks" would probably be better served in the Brainstorming section. The problem for that for me is that Great idea can be used in other sections and still be useful (status messages and conversation threads).
Reviewing my list, if I felt like there was no other way (which obviously there is) I could maybe remove 6-7 reactions but I wouldn't feel good about it. Having a more modular or a better display would, I think, could be beneficial. @Jordan Invision