I am essentially recommending a sideboard, but it doesn't need to be a new game function, simply allow players to delay the 'next' battle in the arena without losing their streak points. Why?
This would force arena deck designers to be creative because, if I can predict your deck from your mark and oracle card, then I have you dead to rights.
This would radically change how we interact with the arena, but it would prevent a major flaw therein: you get a streak going and then you hit one of those decks (DimSh/Immortal/SoWis; FFQ/EBx6/Hope; Devourers/BlkDrags; neurotoxin rush) which (according to the responses on the forum) are 'soooo easy to deal with' if you only had more [PC, CC, Protection] etcetera. No one can prepare for everything, but you don't just need a good deck to collect rares, you need a 5/5 deck (express your success rate as a fraction and raise it to the power of five: the resulting fraction is your chance, per set, that you will make five in a row)
The only alternative os to spend hours a day farming. That is crushingly boring.