I'm going to argue against this, actually. If Joe was as much of a workaholic as he seemed...workaholics don't just deny you emotional attention, but physical, too. They don't come home, bang you and then go to work again; they come home, sleep, are emotionally distant, and then go back to work. Which is pretty much what she described in some of those vlogmas episodes, if I recall correctly. Over time, it becomes a form of manipulation. Even if they do want sex, it is never going to be the kind of fulfilling sex the other partner wants because they just don't have the energy. Couple that with Niomi's perfectionism, and perhaps she wanted to paaahfectly swing from the rooftops while he just wanted to sleep. Sounds miserable and frustrating.
I know we've seen Joe follow a few kinky accounts but that doesn't really tell us much, tbh--the porn you consume is often far more adventurous than you IRL sex life. It's a safe space. Perhaps Niomi wasn't into the things he was into, but perhaps he also wasn't into being emotionally and physically present...those things aren't mutually exclusive.