While I enjoy the current situation, it's unlikely to last. Sometimes we forget that there's plenty of people who have simply built up a clientele and a repuation through plain old networking. These jobs tend to be more lucrative and probably don't require you to learn the flavor-of-the-month js framework. It's no surprise that we don't see many experienced professionals competing for what are essentially entry-level jobs (despite the use of the word senior in the job title and despite the high salaries inexperienced developers command). Obviously not all experienced professionals have built up that network. Those are the people you see applying for jobs.
Source: I spent a couple years getting to know a network of CTO's and architects who have been doing ecommerce since it's inception. They are in demand, they don't apply for jobs, and they are paid handsomely, and yes some of them are grandfathers or grandmothers.