New rune system should give each subclass their own separate runes

I want to first note that ideally I would actually like to see Riot give every champ there own unique mastery/rune trees in a borderlands 2 kind of style, but I know that would be WAY too much work for riot so this it what I think would be the next best thing we could reasonably ask for.

I think the only way to balance runes/masteries and prevent it from becoming like the current system where choice almost non-existence due to most of them being "obviously" better/worse for certain roles/champs, is too give each subclass (Divers, Juggs, Burst Mages, etc) their own runes and work from there.

For example, an enchanter like soraka or sona is always going to take heal amplification over anything else unless there is another choice that is actually competitive against it. Creating a competitive choice against heal amp for Sona/Soraka would be much easier if they only had to work within enchanters rather then the whole champ pool.