That's cause he's the only scoring option in Warriors now, no Durant, no Thompson. He can use ball all the time. His good field goal percentage made this score.
We might see more from him this season. There is no expectation for Warriors, no pressure for Curry.
All-time list of career high can be misleading. If you exclude Wilt Chamberlain and his crazy numbers as that was completely different era and on top of that he was by far most dominant player, and if you exclude last Kobe Bryant game when he scored 81 but that was more like an all star game than serious competitive game, there aren't many games in which players scored more in modern times. Beside Booker scoring 70 and Jordan 69, all others scored maybe few more points in the last 30-40 years.
I do agree with the other part of the post, it is nice to see Curry back, and therefore Warriors. If Thompson didn't get injured yet again, they would be formidable force this season, but without him even playoff would be success and then whatever happens, happens.