Why can't they just be a search engine and forget all this constant updating and tweaking!
I get the desire for this but of course they are going to try to "improve" which requires updating and tweaking - of course many people will disagree as to if some things are improvements or not (myself and many on here included of course).
Ultimately though, Google is out to make money for Google, to consolidate and further its power and control. They do not care about us nor do they care about the users feelings. They would only react to user dissatisfaction if that resulted in an effect on its bottom line or effected its growth negatively.
Re the engineers, I don;t agree that it is a case of the best engineers that created algos years ago having left. Google will have more and even better engineers now but the simple fact is that now google is a monolitic beast with huge teams of developers commiting over 16000 changes per day to their products. They have sophisticated tests within their CI/CD pipelines to try to catch any errors, use a deployment / container management system they developed called Borg (which is the predecessor to Kubenetes - one of the fastest growing technoglies in the SysOps / DevOps world) that enables them to deploy, an rollback changes on the massive scale required.
My point is , with all this going on (do a search and read up on Borg and Site Reliability Engineering if you want to learn about how google manages to administrator is infrastructure - it is on a scale that is hard to fathom) there are going to be the odd glitch that gets through every now and again and that certainly doesnt mean the engineers dont know what they are doing.
I would concur though. along the "dont know what they are doing" line in relation to their use of AI and by that I mean , they dont know what the AI is going to do exactly. By the very fact that AI must have a degree of independence and that it is meant to be able to apply intelligence at a higher level and speed than that of a human, there is no way they can know for sure what the results will be when they implement it. I think this is a key problem with them trying to move more towards AI based SERPs and the AI simply isnt producing results that we and many users think are best. Maybe one day it will do but it seems it has some distance to go to get to that point.