Mostly because I don't know what they know, and in some cases it's just good to start at the ground floor. Some of my classmates were international students from India with only the slightest idea what the difference between a tower and a montior were so having this knowledge never hurts. Also at 44 there may be some stigma that they encounter if they use older terminology or don't know the cutting edge in an interview.

If a cert is useless to you then by all means skip it after doing a practice exam. Talking about your cert goals in an interview is a good way to bring up what you know/are learning on your own.

Certs are there to serve you, not the other way around, so ideally study them until you land a job, then get the job to pay for them if you can.