Absolutely agreed. The Verge already expressed that it saw a drop in Performance between it and normal Pixel 3.
I am shocked at what Google is getting away with here as all this device really has is a good camera, other than, nothing else, and even the Camera image processing is not instantaneous.
I have been saying that people will begin complaining about this device once the honeymoon period is over, right now a lot of people are caught up in the hype.
Of course there is a performance difference between the Pixel 3 and the 3A, the 3's processor is better. The question is, will most people really notice in day to day use? Of course phone reviewers are going to notice -- they tend to use the top end flagships on a daily basis -- either their own personal flagship phone or a phone they are testing.
On the other side, though, we are reaching the limits in current chip technology. While new processors are faster, they are not the 2 or 3x faster than previous generation chips -- which routinely occured a few years ago. Instead, they are incremental upgrades, with much of the performance increases being brought about by improved manufacturing techniques (such as going from a 10nm process down to a 7nm, or now 5 nm).
In fact, where much of the improvement is found, in newer phones, is in adding additional processors -- such as the Pixel Visual Core, with the 3A series is missing.
But my point is, as a mid-range phone the performance is about what you'd expect -- and in average daily use, most people aren't going to notice a real difference between it and a flagship. Yes, photo processing will take longer, at least for HD and Night Sight shots. Additionally, it isn't going to do AR or VR as well as flagships -- particularly as that is an area where special processors maybe added to the flagships to help improve speeds.
Of course, this is also, I believe, one of the factors why people aren't upgrading as frequently. The average user no longer needs a flagship to do the things, with their phone, that they need. We aren't seeing major improvements that the "average user" cares about. Yes, having a bezel-less screen is nice, but it is really worth a hundred or more extra dollars to get, for the average user? The average user could care less about the under screen fingerprint sensor, particularly when it doesn't work as quickly or reliably as the one on the back of the Pixel 3A -- those type of "cutting edge tech" features are the things we phone geeks get excited about.
My guess is that most people won't have an issue with the 3A over two to three years. Again, flagships aren't really getting that much faster -- and they are already almost as fast as decent laptop computers, the average user doesn't need that type of speed in a phone. Yes, they won't get quite as quick of pictures, but you kind of know that is a trade off when you buy a mid-range phone, and most won't care about the speed when they get the great pictures that the Pixel delivers.
I don't think the software updates will "slow the phones," as Google is trying to make Android work well on all phones -- including the cheap budget phones for third world markets. Yes, you might not get access to all the cool new features in Android S -- but you'll get Android S and I suspect the phone will run it fast and competently.