We have a ring in a similar location. We don't have a switch, but seeing your question made me recall my agonizing over whether it was mounted too high. I've never really thought about it since-- so many things are like that! I think it will be fine as long as you can reach it easily.

Put something you like to look at (art) on that wall. Just fold a nice washcloth in thirds and lay it next to the sink for washing hands. They are relatively cheap and you can change them out each day.

-Babka

We have a similar setup and I put a towel ring on the wall so the towel falls just above the switch. It's a little on the high side but nice to have a towel so close to the sink. I don't recommend a hook - the towel would just fall off. Another option is a countertop towel ring that can be next to the sink against the back wall.

Here is a link that might be useful: example of countertop towel ring

We have the same set-up in our guest bath. Drying at the opposite wall isn't the best solution. After 10 years, we finally installed an 8" wide hand towel bar 21" above the countertop. It's not too high, and it holds the towel away from the wall a few inches so we don't drip down the wall. Shop around as some holders extend out further than others.

I have two bathrooms with towel rings in that location (and toilets to the left) and both have outlets in similar locations. I took a folded hand towel (to simulate looping over the ring) and hung it so the towel hangs just above (maybe .5-1") the countertop. I really like having the hand towel there. It means that no one is crossing the room with dripping hands or potentially dropping a towel in the toilet (if I hung it over the toilet instead). I don't think there's a right or wrong answer, it just depends on what looks and functions well for you.

I prefer hooks to rings. But, besides the wall, have you considered mounting a small hook on the vanity itself?

Here is ours. The vanity is only 19" deep and we were contending with not only light switches but also a plug. The plug rarely gets used so I positioned the towel ring so that the towel just comes over the switch plate. No issues and I really like the towel ring.

I would put a towel ring there, or a very short towel bar. If the bathroom gets lots of traffic, I'd also add a folded towel on the counter, that you can change out every day.

Thanks everyone. We held the towel up in various ways and the kids decided they liked a bar up above the switch. Since they'll be using this bathroom the most that's what we'll try.

In addition we'll have a large towel on the opposite wall. Seeing all the pictures and hearing about all the other methods helped a ton!!
Gale