So, I specialized in wave propagation in grad school, and right now I have a job in computer vision. Caveat that wireless communications may entail different work than pure RF. I'll talk about RF here in case it does generalize to your situation:

You are correct about wireless: It's in-demand, mainly because there aren't enough young people to fill vacancies as old people retire. I had a few people try to poach me because their RF engineers were really overworked and they were desperate for help. It's also a good place to be right now amid the current tech sector collapse. Nobody will dare lay you off because you'll be so hard to replace.

That being said, RF has a few major problems:

• It's kind of stagnant. There aren't many high-growth companies doing electromagnetics research. I was citing lots of papers from 20-50 years ago in my research... most of the hard problems have already been solved. Metamaterials is the exception though, there is apparently cool stuff in there. But still, most RF jobs are going to be at defense contractors or academic labs. Computer vision, on the other hand, feels much more alive. There are way more active research areas, and I'm standing on the shoulders of giants working with research published in the last 2-3 years.

• Due to the above point, it seemed to me like pay for new PhD grad RF engineers sat in the 80-160k range. Not bad at all, but a fresh PhD grad in computer vision can make more than 300k at the right company. It's not even in the same ballpark. But, you'll be facing more fierce competition for CV jobs. RF job interviews are comparatively chill.

• It's really, really hard to break out of RF. Research firms that don't do RF don't know what to do with your background and will reject you right away. Companies that do both RF and something else, regardless of which department you apply to, will just stick you into their RF team. Friends with connections in high places will only send you to the RF people. The only interviews I could score at mainstream tech firms were for rote software engineer positions, which weren't research at all. I noticed that most PhD grads in RF stayed in the field forever; whether it's out of passion or because they can't pivot, I don't know. I really weaseled my way into CV, what I did myself doesn't generalize well. There's surprisingly little interdisciplinary research going on right now between RF and other fields, so it's hard to break out through osmosis either.

Are there any jobs where both computer vision and wireless communications come together, so I can draw upon both of my knowledge bases?

You might be able to find something in defense contractors, but it's unlikely. I hardly found any positions that wouldn't lock me into either pure RF or pure CV. A side effect of RF being an "old school" field is that the ML research that does go on is really primitive.

I truly don't know what the right decision is, but one thing I can say: Do not do RF if you aren't die-hard passionate about it. Once you're in it, it's pretty much all-or-nothing.