From the highlights of the second SF, it seemed like Medvedev was striking the ball so well and hitting with a lot of depth and consistency. As his best, he is formidable on hard courts. It seems to me that his serve isn't quite as good currently as it was when he won the 2021 title, but that his groundstrokes are definitely at the same level.
I did think that on the back of their Indian Wells final earlier this year, even more so than their Wimbledon SF on grass where Medvedev is far less comfortable, that Alcaraz's style made him a horrendous match-up for Medvedev (notably exposing Medvedev's return stance). However Medvedev adjusted and had other ideas yesterday, and Alcaraz (of course still a baby for modern day tennis standards especially on the men's side) struggled to hang with him from the baseline yesterday.
I don't know how to call the Djokovic-Medvedev final. 2 years ago, I thought that Djokovic's 5 set SF win against Zverev took a lot out of him, and he had the huge pressure of trying to seal the calendar grand slam. This time he doesn't have that pressure, and apart from 1 match has had a serene route to the final. If this was an Australian Open final, I'd back Djokovic to win (it's interesting to think that Medvedev was actually the bookmakers' favourite ahead of their 2021 Australian Open final match), but with this being the US Open where Djokovic has twice as many defeats in finals compared to victories, I think it's 50-50.
The US Open is the one grand slam that Djokovic has underachieved at title-wise given how amazing he has been on hard courts for such a long time - I tend to think that he simultaneously overachieved at Wimbledon and underachieved at the US Open - he could quite easily have something like 4 Wimbledon titles and 6 US Open titles instead of his actual distribution. Another US Open title before he retires would round off his career nicely IMO.