To start with, the short version is that neither are actually plausible given our current understanding of physics. Faster than light travel or communications are entirely inconsistent with the scientific concepts of relativity and causality. If Einstein's theory of relativity is true, there is no difference between faster than light travel and a time machine. Both time machines and FTL can easily lead to situations that allow causality violations, which is the idea that if event a causes event b, event a must occur first.
While you could then say that Einstein's theory is incomplete, you would still need something that makes the same predictions, which includes calculations that let the GPS on your phone work and explain why the orbit of Mercury is stable. New theories can't simply say old ones are wrong, they have to explain the same phenomenon that the previous theory as able to explain in addition to the new one.
Having said this, I also understand how hard it is to make a space setting that doesn't cheat on this, which is why nearly everyone does it(bizarrely even those who don't have FTL travel often cheat on FTL comms, which are equally bad). Even settings like The Expanse that otherwise follow physics eventually wind up cheating to allow interstellar flight(and stealth, but that is a different issue). I guess this is my way of saying that the actual realism of either mechanism doesn't matter. What matters is which you'd rather have in terms of story options.
The big differences would come in how the technology is discovered and what we wind up doing with it. Wormholes are more likely to be discovered rather than created outright, though it could also be a possibility that they can be synthesized once they are discovered or that they can be controlled in different ways. The strategic situation revolving around wormholes is mostly what you see in Mass Effect with the mass relay network. The advantages here are that you have strategic choke points, which leads to interesting strategic questions about how to deploy fleets. There is also the potential dramatic advantage that travel outside of the network is extremely slow using conventional STL travel, which can lead to interesting questions about when things like backup will be there depending on where the heroes are relative to the network. Another effect here is that wormholes are an example of a technology that increases centralized power, as a government or large corporation with the resources to control it would be able to restrict access(if Star Wars had a wormhole network, it would have put a damper on both Han Solo and the entire Rebel Alliance). If the heroes are fighting against the system, they would have a hard time traveling between star systems given that some kind of wormhole port authority would inevitably be created.
Alcubierre style drives are likely going to be slower but much more flexible, in which they can allow much more controlled journeys to wherever your point your spaceship. The downside is that you now have another worldbuilding question that must be answered. If you have the energy abundance to sustain FTL travel and synthesize the negative mass required to make it work, how do you still have something to fight over? If you can synthesize negative mass in the quantities required, you can also synthesize any element on the periodic table just as easily. There would never be any real need for conflict given this level of energy abundance, which probably means you have either cheap fusion or a functioning Dyson swarm that takes in nearly all of the energy from the sun.
Of the two, I'd say that wormholes lead to less other story problems, but that Alcubierre drives lead to more flexibility in terms of how easily ships can travel to wherever they want. If your goal is a degree of realism, I'd probably go with wormholes because of the consequences implied by an Alcubierre drive.