There seem to be varying opinions on whether it has any benefit or not, but my own experience has been very positive.
For around 10 years I’ve had aches in my glutes. Didn’t think much of it for a long time. It gradually got a little worse, not really bothering me so much on the bike, but more so afterwards. Eventually it got to the point I would sometimes have to stop the car and sort myself out after a ride because it ached so bad. Then it started bothering me sitting at work, driving home – basically all of the time. Couple of weeks of stretches after riding sorted it out completely (I did stretch before that, but had never found anything that actually stretched my glutes). It’ll start to come back again if I don’t stretch for a couple of months but a couple of days stretching sorts it out.
Generally I feel fresher and looser stretching after a ride. Removes all that stiffness. I am by nature completely inflexible, so that’s perhaps part of the reason I find it so invaluable.