No, it's not. RNR and TT can have rather lengthy SR lines...shorter than standby? Yes. Shorter that FP? Rarely.
RNR can bea s long, if not longer, than standby. They even close it off because it has gotten too long.
10-15 minutes seems about right. I don't think I've ever been in the SR line longer than 15 minutes.
TT has always been shorter than standby, and I've never seen them close the line. That said, I have had to wait 30 minutes for it on occasion.
This one is hit or miss, and the only one I've waited in where it was longer than the SB.
The problem with the SR lines is that too many larger parties (parties of 3 or higher) are using them. I would argue that single rider lines were developed with the thought that really on single guests and double guest would utilize them as opposed to parties of 5 and more. Yet is seems large groups more and more are using them, which increases the SR wait times. Disneyland's aren't nearly that bad. They aren't too obvious, as most SR entrance are through the exit or a separate entrance that isn't clearly visible to people getting in the standby line, so large groups don't just walk into the SR line when they see the wait times for SB, and you have to get a pass from the CM hosting the standby or FP entrance.