They used to let Alves raid down the right for years. He was like a 3rd wide player. So I'm sure they could give Vidal the same freedom if that actually believed in him.
Roberto has been in great form though.
They're too different, Aleix can't do the same work imo, Alves was a RB in defense, another CM when his team got the ball and a RW when the ball reached the last third. He didn't just have stamina and speed to spare, his tactical awareness was top level and that was key for his "3 position player" style. In his final years he lost some stamina and speed so his errors became apparent because he would always appear in the photo of defensive mistakes, he still had the right instincts, but his legs were not the same.
Aleix is, at best, 2/3rds of the player Alves was, he is quick, he works hard and has stamina to last 90 minutes, he knows when to run forward but that's it. Alves was better on the ball (so, the 3rd CM role helping in play build up won't work with Aleix), he also lacks the tactical discipline from Alves and his awareness, Alves was a genius at tactical fouls, he got away with a lot of 50/50 duel calls from the ref, he knew how to use his body to block or displace, and even if I don't like it, his teathricals helped him a lot in those situations. Aleix constantly loses duels against wingers, they usually throw him out of position with their body and even if he manages to catch up again he just loses another duel, he doesn't know how to master tactical fouls, either not fouling at all or doing it in a way that usually gets him a yellow card, I thought he would be able to claim the right wing, but he is lacking some aspects that are required in Barcelona's 433, aspects that Sergi Roberto already has, good ball control, CM experience, good instincts to work as a winger, stamina, speed and work rate
Playing for FC Barcelona as a right/left back is hard, a position that works in a stablished way for our playstyle, not the "usual" way. I think Sergi Roberto has the right arguments to be our starter in RB for the next years and Aleix will get crucified after every game, he's had enough time to try to fit (Arda is a good example, he's a different player now comparing him to his 9 months ago version) so it would be best for both, team and player to part ways, he could do a terrific job in a 5 man defense, just like Alaves' Kiko Femenia did this weekend, another player that struggled for some years between the RB and RW positions but really shines as a full back in a 5 defensive line that covers his flaws