I've run AL games in two states. Most players are taking them this season from what I've seen. Last season, not so many did.
I've only seen two feats that gave me pause...
The human ranger (Variant human) with Archery FS took Sharpshooter. He was 16 Dex (+3), and proficient (+2) and had (at level 2) +2 more from Archery... for +7 to hit at level 2 with his longbow... and could roll at +2 instead of +7 out of the gate. (Int was his dump stat...)
Likewise, a Variant Human Fighter with Great Weapon style and GWM... Only +5 to hit, or +0 and +10 damage... and using a greatsword... In AL play, vs stuff with level appropriate AC's in the 11-15 range...
So... let's do the math.
GWF
+5 means needing between 6+ and 10+ to do an average of 11‡ per hit... or an average of 8.6† DPA vs AC 11 and about 6.45† DPA vs AC 15
+0 to hit and +10 damage per hit... needs 11 and 15, respectively for an average of 21‡ per hit, DPA 10.9† v AC11 and 6.7 vs AC15
DPA: Damage Per Attack - accounts for hit rates and damage per hit.
‡ +1 for GWFS
†Including crits.
The Great Weapon Guy only gets better vs harder targets, where the chances of hit are mitigating the average damage.
The Ranger, with his 1d8 Longbow...
+7 and 7.5 avg damage, same ACs... AC11 is 6.6 DPA, and AC 15 is 5.1 DPA
+2 and 17.5 avg, same ACs... 10.7 DPA vs 11, and 6.875 DPA vs AC15.
That ranger has no reason not to use the increase if he can stand-off and fire... he's getting enough extra to make up for the lost hits.