Suffers from the same issues the Bourne movies do.
If a movie series goes on for too long and has a somewhat more complex story than for example the Harry Potter series, it gets too convoluted over time. Too much baggage basically. I don't care anymore who works for whom.
Who's a double-/tripple-/quadruple-agent? I just don't care. It's lame that you can anticipate that whoever is new to the series will be one. Ethan Hunt knows yet again about the most absurd setup to trick him and how to get out without explaining it to the audience? Yawwwn.
The villain isn't killing our heroes when given the chance because... to enable the resolution at the end? Why kill someone by snapping the neck, or putting a bullet in the head if you can hang him instead, right? Because it's more suspenseful? No, no it is not. It's just extending the screentime unnecessarily. It's lame story telling.
Why is Benji slowly hanged while the "pretty woman" is just tight up? Weren't they all going to die anyway according to our mastermind Lane? What was that about? That whole setup was ridiculous.

There's a lot of action, yes, but no suspense whatsoever. We all know how this movie will end - more or less.
It's a typical shut-your-brain-off action movie you watch in the cinema and will forget most of it when leaving already.
The whole movie follows a too simple formula with an action driven resolve at the end to give the audience a good feeling, deluding from all the issues that is has. Simply a forgettable movie all around.
Although not the weakest of this series but not the best either.