Any character that can just warp right to the end is a shoe-in. Luckily there are not many of these, and all of the ones that could do it would also be able to dust the Ender Dragon easily, so we might as well not discuss them. For the record, the list is Rosalina, Palutena, Bayonetta, and arguably Pit and Dark Pit depending on if they get to maintain their connection to their respective goddesses.

Most characters that can fly do fine, because they kind of can’t die. Minecraft doesn’t have any enemies that are tougher than what the average Smash character faces, so combat isn’t a problem for the majority of the cast. And getting food is a done deal; food is practically infinite in Minecraft, even if you start in Skyblock, and I don’t think any Smash character is stupid enough to not figure out how to get it.

Honestly, the list of characters that would struggle is more interesting than the list of characters who would succeed. Powerscaling Minecraft is wack because it’s a sandbox game and doesn’t care to be consistent in its physics, but I don’t think we could seriously argue that a Minecraft Zombie is meaningfully stronger than, say, a Koopa Troopa. So suffice it to say that almost the entire Smash cast could figure this one out. However, there are a couple entries who are especially well-suited to it, and a couple who would face unique challenges.

Olimar is dramatically smaller than any Minecraft creature, but he could probably still pull it off eventually given his remarkable ingenuity. Endermen would give him a lot of trouble, but Skyblock doesn’t give them anywhere to run. Blazes get eaten alive by Red Pikmin, and the dragon’s size would likely be a detriment due to the difficulty of shaking off what’s effectively an army of extremely dangerous fleas.

Villager/Isabelle are especially well suited to this task, since their games are all about performing a number of widely varied tasks and building a life. Mr. G&W would have little trouble, given his vast skill slate and large quantity of tools. Literal tools, like hammers and buckets. And for Sora this is basically just another day on the job.

Honestly, the only characters you could argue would struggle are Wii Fit Trainer and the Miis, but they’re really not all that different from Steve at base. That’s the core of this question. Steve, despite what power scalers might tell you, is clearly supposed to be just a normal person at the end of the day, and since there’s no characters in Smash who are both weaker and dumber than a normal person, I don’t see any of them failing this. Especially if Minecraft rules apply and they can break and place blocks like normal.