All purges prioritize short duration buffs over others, or even better, allow players to specifically choose certain effects to get rid of first.*
All purges have at least a short CD.
Major class functions become Faith In Action style passives.

Every purge related problem solved, forever.

Nobody can spam purge off an entire bar of bonuses, but now they actually wipe out dangerous buffs (Healer's Covenant, Neddra's Essence, Swift Control, Spell Reflects, whatever) instead of just purging yet another pair of Bard motifs (you want more tactical play? there is some). Also; nobody has to listen to someone complain about losing Lifegiving Veil ever again.

*Would be nice for cleanses, too.

I don't know why we even have purges if most people in the enemy team has 10 buffs up at once (up to 6 bard buffs, 3~5 stat buffs, 1~3 self buffs, and THEN the temporary high-power buffs you actually care to get rid of), but a no CD purge is not a solution.