It's always around.

It's extra around right now because of COVID, in two ways. First, peoples bodies are busy fighting off COVID basically all the time, and as a result other pathogens are able to survive a bit better, sometimes much better, and RSV is surviving long enough in the body to make it to the lower airways, where it can cause breathing issues and normal viral fever, aches, etc. Second, people aren't being as sanitary with distancing, masking, hand washing, cleaning, and eating urinal cakes again and so forth, and so lots of people who didn't have it for a long time are getting it again, lots of kids getting it for the first time, so their RSV antibodies are low or non-existent, and it survives long enough to become symptomatic, which includes cough-spraying droplets of lung fluid, spreading the virus.