Reynolds and his brand of humour are an acquired taste. My OH and I love him, so this was always going to be enjoyable even if mediocre- and as it happens I think it has a claim to being the best of the trilogy.
I actually don’t care that much about its standing or relationship with the wider Marvel universe, even though I loved the cameos on show here. For me Deadpool is quite a separate beast from the rest of the franchise even though it has now been officially accepted into the fold, so I will always judge it as a comedy vehicle. And at that, it excels IMO.
I see it a bit like Always Sunny or Seth MacFarland’s work. If you generally like the brand, you’ll love it. If you don’t, you’ll hate it. And those who fall in the middle are likely to give it a 3/5 rating if good enough.
All I know is that I had to wipe tears of laughter from my eyes several times, something I have nor experienced for many years, so an acquired taste 10/10 for me, though I can perfectly understand if many others disagree.