If you open a new credit card account and close it soon after, the net change in your utilization % will be zero because it increases when you open the card and decreases by the same amount when you close it.
However, the average age of accounts (AAoA) decreases when you open the new card and does not change when you close the new account (this is true for FICO but not all models). Therefore after opening and closing the new card your AAoA goes down and stays down, but continues to age over time and slowly ticks back up to where it was before you opened the card.
As for if it's worth it, AAoA is a small % of your total score (15% for FICO) so opening and closing a few cards now and then shouldn't affect your score very much.
Side note: I've heard (but have not tried it myself) that you could reverse the decrease in AAoA by contacting the issuing bank and asking them to completely delete the closed account from your credit report. Most people advise against closing the account to begin with, and even if you do they'd also advise against removing it because over time the AAoA will continue to increase. However, if you already have a strong history with multiple old accounts and your AAoA will increase by deleting closed accounts from your report, then it couldn't hurt to try. Typically you would ask the credit bureaus to remove accounts from your report rather than the issuing bank, however the bureaus are less likely to remove correct information that is also non-negative, so this is why it is suggested to ask the CC issuing bank instead.