WARNING: OPINION What I mean is that honor 5 could be only for people who are in the top 15-20% of honorable teammates, rather than just having anyone who carries a lot getting honor five almost immediately. This way you actually have to be honorable to get higher ranks of honor, rather than just getting random honors from teammates
Honor should NOT be a contest.
Limiting it to a percentage would not work and might even have an opposite effect. If I know that only, lets say top 10% are allowed to have Honor 5 and I just got Honor 4, then I see my chances of ever getting up there as being slim to none since I am just a normal player, only player a few games a week out of boredom. So I would not event try to be honorable at that point, as long as I am not a complete asshole in game (or just don't get caught being one) then I'll stay Honor 4 and still get the rewards, but I no longer really need to be "honorable" to anyone. On top of that, what constitutes "honorable"? Even just among my roommates I know we honor people for different reasons. I'll personally always honor someone in my party (randomly if more then 1 person) or a good healing support, while I know one roommate solely votes for the person who he things did the most in kills or objective pressure (if it is him he will vote for no one) and the other only votes for party members and never votes when playing alone. Streamers would probably have a very easy time of getting Honor 5 if you limit it to only the top percents since they are typically always voted for even if they are not necessarily the most honorable or most useful.
The whole Honor thing doesn't even matter anyway, as long as you aren't Honor 1 or 2 you are pretty much on the same playing field. All it effects are random item drops and , don;t quote me on this, I think once you hit Honor 3 the drops do not increase for Honor 4 or 5.
but that would mean that the 15-20% would be filled fast and people would have to drop out for no reason to give other people a chance to be Level 5.
Riot has mentioned a good few times that the reworked Honor System isn't based on the number of Honors you get - those are only a small factor in your Honor Progression. All we really know is that it's a whole heap of math and that individual Honors (from non-premade teammates) and Group Honors (where everyone honors someone in post-game) has some small impact on your Honor progression.
(which, that also means that carrying games has no effect on your honor progression.)
On another note, how would you even decide if someone's Honorable, let alone that they're one of the top 15-20% of Honorable players?
To climb to higher honor rank, all you need to do is play a lot of games and don't get punished. Your top 15-20% would just simply be the people who plays more games than others. There is no reason at all to restrict access to honor 5. Not to mention the fact that the ONLY way to lose honor would be to get punished. Once you are in said top 15-20%, you are "locked" in (i.e. no one else would be able to get honor 5 after quota has been filled) so long as you don't get punished. That would be silly to literally lock 80-85% of player base out of honor 5 for the entire season.
