I suppose it’s about intentions, but as someone who always looked to settle down and find the person to live the rest of my life is, a big agegap can be pretty problematic later in life.

Like the obvious one: your partner dying while you’re still just middle aged.

Having to take care of an old person with old person needs as a 55-65 year old.

If they want children in a few years, OP could be 75 by the time the child moves out.

Again, it’s all about what the intentions are, but these things are worth considering.