'Dynamic campaigns' are seemingly preferred because they don't ship with canned missions- so seemingly giving you a different game every time, but not really. The campaigns are really playing out the same way every time, usually there's a lot less specific goals in mind. The computer has to be programmed with a generic set of instructions that work in each and every circumstance, a one sized hat fits all- consequently, it has to do all things, but not necessarily exceeding really well at any of them. So while a canned mission might task you to attack and defend a bridgehead, then retreat or relocate and defend a new position or assault a new location, dynamic campaigns really don't achieve that level of 'dynamic' mechanics. It's more generally, attack, defend against attack, or follow a set of waypoints, destroying everything along the way.
The best dynamic campaign would be one run entirely by humans rather than by a computer.
Just look at Falcon4 (BMS for example). You have several types of different missions, I would dare to say more mission types than any Static campaign that I ever saw.
Yes, I admit that with static missions (in static campaigns) you can have all sorts of triggers and events that can result in your mission objectives being completely or drastically changed (sort like storyline). BUT on the other side the player will only successfully complete any static mission once since these missions always play the exact same way a thing that doesn't happen with a dynamic campaign since missions are automatically generated each time a campaign is started and depending on previous mission results - While yes, some missions in a dynamic campaign will or could trend to repeat themselves but since these missions are generated automatically and randomly the player will never have the EXACT same campaign experience everytime he/she starts a campaign.
Besides and also adding to the random factor, in a dynamic campaign every unit (aircraft, ground vehicles, buildings, etc...) that you or your allies or your enemies destroy will be destroyed in the future - A dynamic campaign keeps track of every unit and its status within the battlefield, because of this if you play an exact same mission that you previously played you most likely won't find the exact same enemies (aircraft, air defences, etc...) that you did last time (a thing that of course doesn't happen in a static campaign)
Regarding "a dynamic campaign run entirely by humans rather than by a computer", this means that:
1- You must play in Multiplayer
2- At least one human (for each side) must play as a Supreme Commander
And guess what --> I don't like to play combat flight sims in Multiplayer (except for very rare times and ONLY in CO-OP) and I also don't like to act as a Supreme Commander (specially in a combat flight sim). So for me, the best campaign is still an AI controlled and generated dynamic campaign.
I won't say that there couldn't be some advantages in a static campaigns (for example in recreating historical missions) BUT the advantages of a dynamic campaign far surpasses the ones in a static campaigns (for example: repeatability and randomness).