-
first idea is a ban of 1-5 champions you could possible pick for your lane/role plus 5 more possible counter bans, with 139 champions on league that only can drop your champion pool down to 129 champions, assuming you wouldn't queue into a role you only own 1 champion for that gives you plenty of wiggle room to just pick a new champion
-
strategy bans and picks, it's only natural to ban champs that can easily counter you and banning high win rate op champions is part of that strategy so unless someone is going to first pick or risk it for biscuits on a second pick, it's not toxic to remove that champion from the equation, and as previously stated you still should have a few other picks.
-
the lesser obvious argument for banning hover champs is just to many priority picks, if your team is hovering multiple top tier champions atm, you gotta make a choice between being greedy to try and get them all risking giving them up to the enemy or to simply ban out one of more of those hovered picks (personal example: i have lost my pick to the enemy do to the fact i first picked Vayne for our team, forcing me to change my champion of choice (which was limited by who my teammate has on his roster), forcing an awkward pick from me)
The only bullet point i can think for locking a champ as unbannable is true "first pick", it's the first champion selected from either team and as long as it isn't banned it is guaranteed to be selected....... except if that person decides not to lock that champion anymore for some reason, which could then allow it to be selected by the enemy, which could be tilting to your own team because it was locked out of being bannable. which allows the ability to troll your team in a way. now if you extend that lockout ability to 4 other people, you can essentially unlock a new method of trolling..... getting the picture? a personal example could be 3 months ago i didn't know how to play zed, i finally decided to play him and i'm decent at him, but the biggest lesson i have from playing zed is i know how he plays now and i no longer ban zed, ever. i once viewed him as a must ban and now i view him as a wasted ban. i could theoretically hover him to prevent a ban i'm not scared of and then select a new champion after the matter, trolling my teammates and frustrating them if he gets picked on the other side. Yet another argument can be made against this is to just locking a hovered pick and forcing that pick, but this completely undermines and is counter intuitive to the ban/pick process that is meant to be a staple part of ranked which is picking and playing champions against your enemy comp. as picks play out, so this is not a solution either
TL:DR the system works fine, people should have plenty of other options if their hover does get banned and people should always be mindful of how unfavorable a champion is to play against so be untiltable if your teammates simply ban it out.
The best we can do is report those becoming toxic over the matter and hope the fields of justice can stay clean of such negative player interactions
