Hugo Weaving may not have been present in MCU’s Phase 3 finale with the Avengers Infinity War and Endgame, but Red Skull was, as “Stonekeeper”, otherwise known as Johann Schmidt, also known as the Red Skull. However, he was completely CGI in those movies and voiced by Ross Marquand in both.
Turns out Hugo Weaving was originally meant to come back, and he would have done it, but some things just didn’t work in the actor’s favor, something that Weaving states was due to issues in negotiations with Marvel. Here is what Weaving had to say about it when he spoke to Yahoo! Entertainment recently:
“Oh, yeah. I loved playing that character Red Skull – it was a lot of fun. We were all obliged to sign up for three pictures: I was thinking [Red Skull] probably wouldn’t come back in Captain America but he may well come back as a villain in The Avengers. By then, they’d pushed back on the contracts that we agreed on and so the money they offered me for The Avengers was much less than I got for the very first one, and this was for two films.
And the promise when we first signed the contracts was that the money would grow each time. They said: ‘It’s just a voice job, it’s not a big deal.’ I actually found negotiating with them through my agent impossible. And I didn’t really wanna do it that much. But I would have done it.”
Unfortunately, it seems the multi-picture deal that Weaving had with Marvel to appear as Red Skull in three or so more films fell through, and only one (not counting flashbacks or dream sequences or anything like that) ended up happening. That’s just how it goes sometimes.