I am turning 40 in a year and almost everyone I work with is 15 years younger than I am. My opinion is that you have it all wrong. I don't think younger engineers are hostile to old age, but culture fit is important. It's not about your age but how you carry yourself. Until you're in your 70's you can probably afford to make an effort to understand the culture of 20 somethings. You can look to speakers at tech conferences and many are probably as old as you and I but don't have any problems fitting in with their younger peers.
You just have to be willing to adapt yourself to fit in with who you work with. If you aren't interested in making personal changes because you shouldn't think you need to just to earn a paycheck then well you're probably not a good culture fit. You need to make an effort. I enjoy the same things my peers do, we play the same games, we watch the same things and read the same websites. It's not fake with me. I'm not trying too hard. I'm just not getting stuck in old ways.
You just have to be willing to adapt yourself to fit in with who you work with. If you aren't interested in making personal changes because you shouldn't think you need to just to earn a paycheck then well you're probably not a good culture fit. You need to make an effort. I enjoy the same things my peers do, we play the same games, we watch the same things and read the same websites. It's not fake with me. I'm not trying too hard. I'm just not getting stuck in old ways.