“Is optimizing META data still a relevant tactic for ranking in search engines?”
I am an SEO consultant for a dozen different companies and i swear every single person that hires me asks that exact question. The short answer is, “absolutely”.
The long answer is, “a blend of optimized META data, content, and a competitive domain authority is needed to rank in search engines”. For example, a client of mine sells automated external defibrillators and they have a great domain authority with terrible targeting on page. So by simply optimizing their META data they went from ranking out of the top 50 to rank 11 in few week in Google (they are the green line, their competition is red).
However, if you have a very low authority you will need to do a lot more work than simply adding your targeted keyword into your title tag. With SEO it is always a blend of multiple tactics that get you to rank and each site is always different.