As someone slightly younger than 50 I do fear for future career prospects, because yes I might have more experience, but how much is that experience worth to an employer? How often do they need that experience vs just straightforward day-to-day work that someone younger and cheaper could do.
I'm in a field where I know I have to keep learning the new tricks, lingo, and skills in order to stay competitive and that I need to find ways to differentiate my role from that of someone younger.
Good companies do value experience, but sometimes that experience comes with complacency and a lack of willingness to grow. I've managed folks across wide age range (interns to 55+) on the same team, and while the experience / maturity counts, it's sometimes hard to make the argument that the additional "experience" the 55 year old brought to the table was even necessary on the type of team I had. So as a manager you need to nudge people up or nudge them out, there really isn't room for people to just stay on doing the same job for 30 years.
Staples screwed up big in that way. They kept people on in dying tech roles without any support to grow / learn, add skills and then when things changed, those people had nowhere to go. Of course people should be motivated to grow themselves too, but Staples did a really terrible job of meeting employees half-way (few training opportunities, barely existent tuition reimbursement, etc)