For the past few years the recaptchas I've seen were illegible text next to easy to read text. I think its obvious that they've run out of the low hanging fruit and now just have the worst of the worst as placeholders. The move to house numbers just proves that they're kinda running out of badly OCR'd text.

This move isn't too surprising. OCR based captchas have always been a hack and the "best" captchas are like having the best collection of duct tape and WD40. At a certain point you need to stop doing half-assed repairs and remodel.