I think the plot was hardly there, the multiverse & timelines make anything confusing, and there are a few plot holes. But as others have mentioned, it was an enjoyable 2 hours with a few fun surprises.
Some of the bigger problems for me
1. Wade & Vanessa's relationship is a huge part of the first two movies. They hardly touch on why they aren't together.
2. The multiverse and timelines have rules that they pick and choose to follow. It is confusing trying to follow any plot involving them. I wish this would have reset back to where the sacred timeline is the only timeline. Maybe Secret Wars will finally do this. But that is what, 8 years and dozens of movies away?
3. Why doesn't Cassandra Nova kill them the second the helmet comes off? Just a minute earlier this was the case. All because she heard a story of how her brother in another universe was a good guy? The brother that in every universe tried to kill her in the womb and she never knew. Because she was sent to the void shortly after that. A woman who is straight-up evil. But nope, she lets them live. It is the usual trope of the bad guy letting the good guy go to come back and spoil the bad guy's plans. THEN seconds after she sends them to their universe, she hires the Deadpool army to take them out anyway. What?!
I will say Cavil as Wolverine looked a little weird. I'm not against it. But he's getting up there in age as well. Could he play the character for another 10-12 years? Or would he want to?