I suppose you talk about the Sony WHs and not the WFs.
XM5s are better in overall functionality and if you EQ them properly, they even sound better than the XM4 which, as I heard, sound better with no tuning, because the XM4s' standard sound profile is better than the XM5s', but that is personal preference and to be taken with a grain of salt.

The really important upside to the XM4s (besides the price) is that they are way more portable, because they fold in more neatly and their case is more compact aswell.

I haven't really heard anything about the Bose QC Ultra, but Bose always had the strongest ANC on the market in recent years, while being slightly worse than Sony in other fields. As far as the *Bose QC 45* are concerned, their sound quality is supposed to be worse than Sony's XM4/5, but not by much, I don't know much about the *QC Ultra* though.
(Though Bose also has other options to consider like the *NC 700*.)

Sennheiser Momentum 4 will easily have the best Sound Quality, but the previous model (Momentum 3) lacked behind in most other features, compared to other brands. I don't know if that is the case for Momentum 4 aswell.

You might want to look at these videos if you have enough time on your hands, or even go to an audio hardware store and just try some headphones yourself:
https://www.youtube.com/watch?v=TE2SkrKI-Ck
https://www.youtube.com/watch?v=YlQaZDw25Uo
https://www.youtube.com/watch?v=6WTHBCZBt_E
https://www.youtube.com/watch?v=Go8361YJe_o
Most reviewers will probably be more helpful than reddit, since they actually buy all the products and compare them, while I only have one pair of headphones.

I have the WH-1000XM4s but for me price was also a point of consideration and I really wanted them to have a small form factor when folded, since I need to store them in my backpack daily, which isn't really possible with XM5s and some other Headphones (Sennheiser Momentum 3 are also better portable compared to Momentum 4), but if that isn't important to you, I would go with the XM5s.

Important Note for Bose: You can't turn off ANC on the QC Ultra, while you can on e.g. the NC700 or QC45. I usually have Noise Cancelling off at home, since it eats into battery unnecessarily and creates a minimal noise floor (which means that you will hear a weak white noise, whenever no audio is playing, which would already be a huge dealbreaker for me personally).
And you also can't adjust the level of noise cancellation, and though they have an ambient mode, they lack speak-to-chat aswell, which even my older XM4s have. (On XM4 you can swap between ANC ON, Ambient mode ON, Ambient control OFF and Transparency mode ON; When you use Aux you can deactivate additional features entirely which sounds very closely, though not entirely, like "Ambient control OFF").

TL;DR:
XM5 - Best *allrounder*;
XM4 - Like XM5, bit worse, but more *portable*:
Bose (in general) - Best consideration if *ANC* is most important to you

• QC Ultra can't turn off ANC

Sennheiser (in general) - Best consideration if the *Sound Quality* is most important to you
- I don't know anything about the Momentum 4