There is a lot of discussion on this, so will expand a bit.
When Webber assembled the squad before the season started he had a lot of players to upgrade on, players that may have served us well, but really aren't up to this level. I'm talking about Leitner, Vrancic, Tettey, Stieperman, Hugill and Hernandez. He had a certain budget to be able to do this, so was spreading himself thin to start with. He will have scouted Billy, and identified him to be a Leitner/Vrancic replacement. He also scouted other players to come into the midfield (Lets not forget the Skipp sized hole in our team too) as a whole unit.
Farke played Billy sparingly, to begin with, mainly as he had a few other options, but as time has gone on he has become first choice, not so much through great performances, more so out of necessity, due to injuries. And as players have got injured, Billy has had to take on more responsibility, where we are in the situation where we are literally looking to him to win every single game for us. Is it fair on him? Probably not. But it is what it is, we had ten first team players missing yesterday, and a back four that barely know each other, never mind having played together.
Would Billy look world class in a team with the movement of Havertz, Kante, Werner and Lukaku around him? Of course he would, I could probably look good in that team.
Is he the wrong player for us? Not at the start of the season, no, but now that he is having to take on a role that has been forced by our injuries, possibly. It is definitely worthy of note too that he played the Villa game with a temp of 39 degrees, so assume he has had Covid, which would explain low energy levels. But we could really do with the club explaining a bit more about this, because it is an obvious factor in some players performances over the last few games. He's a young player playing his first full season at this level, but what has definitely not helped is Chelsea fans battering us with the opinion that he is world class, and way too good for us. He's a great young prospect, but do I see him as a regular in the Chelsea midfield next season, not sure. If he was as good as he is being bigged up, he would be in the Chelsea midfield this season.
And too much has been made of that fan chanting yesterday, Billy is a loan player, he's always going to take stick, but at the end of the day it is awayday gallows humour, those very same fans will be singing his name next game, that's just how football works.