Djokovic will probably win, but with odds close to 5.0, Ruud is the play. The odds are so high because of a combination of factors and overall it makes more sense that Ruud is a bit underrated here. Some people might not have watched Alcaraz in the semi and / or the previous matches. He played way below his usual level in the first two sets and still managed to be in a winning position after two sets, having played slightly better overall, despite (according to Alcaraz himself) cramps having started at the end of set 2. Obviously sets 3 and 4 are very misleading, so just looking at the score gives people a wrong impression.
Also, while being a very strong clay court player, this is Djokovic's worst surface and Ruud's best, especially considering the size of the court (Ruud likes some additional space). Additionally, there is a chance Djokovic will have some injury problems in the final, like he did in set 2 against Alcaraz, there was something wrong with his forearm (?) and he had to take a medical timeout. [This shows us how little people pay attention in general, literally nobody mentions this, also on other forums.] With the current odds, there actually would be value on Djokovic if it was the Australian Open oder Wimbledon, but here Ruud is the underrated player. By the way, I disagree that Djokovic and Ruud are similar from the baseline, Ruud hits with way more topspin whereas Djokovic is more balanced in terms of forehand / backhand and a bit more attacking.