It's not hiding anything. A resume is a two pages flyer to advertise your services. It doesn't pretend to accurately represent you as a person or 40 years of accumulated experience.
It's really bad if a resume never pass the first screening, it literally can't get a job. It's not reasonable to blame age for that, interviewers cannot guess the age from just a resume (and if they can they shouldn't let be).
Yes, it’s a flyer but it’s a flyer that many expect to include specific information in a specific format. You are free to ignore those expectations of course but employers are also free to draw various conclusions about apparent employment gaps, incomplete work history, etc. even if those conclusions aren’t warranted.
It's really bad if a resume never pass the first screening, it literally can't get a job. It's not reasonable to blame age for that, interviewers cannot guess the age from just a resume (and if they can they shouldn't let be).