Only if graded copies of that exact item sell for meaningfully more than ungraded ones. Not whether grading is good in general — whether it moves the price of this thing.
The sum
Grading costs a fee and takes weeks. So it is worth it when:
the premium on a graded copy is bigger than the fee, plus the postage both ways, plus the weeks of not having sold it — and you are confident the grade will come back high.
That last clause carries most of the risk. A high grade adds a lot; a middling one on something you thought was near perfect can leave you worse off than selling it raw, because now the flaw is certified.
When it is usually yes
Something genuinely near the top of its ladder in a category where graded prices are much higher.
Something frequently faked, where the grader's authentication is worth more than the grade. Often the real reason to do it.
Something expensive enough that the fee is a small share of the price.
When it is usually no
Common items. The grade costs more than it adds.
Anything you have not examined properly. Look at it under a light at an angle first — people send things they believe are mint and are not.
When you need the money this month.
What to do instead, which works better than people expect
Live video is your substitute for a slab. Turn it over on camera, tilt it to the light, show the corners and the edges close up, and say the worst thing about it out loud.
A buyer watching you do that has had a better look than a photograph of a sealed case gives them. It is the specific advantage of selling this way. Can I ask for more photos before bidding?
Describe condition in words as well as letters, because the letters mean different things in different categories. What do NM, VG and the rest mean?
If you do grade
Sell it sealed. Opening it undoes the thing you paid for.
Show the label clearly in the show, serial and all, so a buyer can look it up while watching. What is professional grading?
The honest test
Look at what graded and ungraded copies of your exact item actually sold for recently. If you cannot find that comparison, you do not have enough information to justify the fee — and the default is to sell it raw, described honestly.
More: what is professional grading, how to price for auction, what is provenance.