USUM fixed that by making it to where you can save said consecutive wins, and coming back to play will allow you to start from that point.The Battle Frontier should only come back in a future installment/remake if they change the mechanics on progression. I’ve been doing the gen 4 facilities at the moment and it’s too frustrating to be actually fun (beat the Castle and the Hall with Gold Prints), not to mention how tedious breeding is unless you RNG manipulate or something. In regard to Alola, the Battle Tree is admittedly less annoying because there are only three lines (I’ve gotten 50 wins in each category) and it is LOADS easier to breed good stuff, but it can still be irritating.
Instead of the “one loss and start all over” stipulation they have now, why not have both a checkpoint mode and a traditional mode? Having a checkpoint every 10 or so battles would make it a lot more accessible to newbies who don’t know the ins and outs of competitive battling yet. That way those people who just want to get whatever superficial reward or BP can get it without investing a massive amount of time while losing would only set you back maybe 10 rounds. The traditional mode could be the standard “one loss and you are done” to please longtime fans. The Stadium games had continues for winning a round without faints so there is no reason this artificial difficulty/longevity should exist in 2019 save for the players who willingly chose it.
“But it’s a postgame facility! You don’t have to do it if you don’t want to!”
That doesn’t mean they can’t make little “quality of life” benefits to make the experience smoother and more enjoyable. Look at the more recent Fire Emblem games with the mode letting units revive after a level (can’t think of the name right now) for an example.