Except the update issue I always tell people the opposite, never ever buy a flagship. Usually they have bad screens (in terms of you always only see flagships breaking on a 1m fall) the added software usually is a mess compared to original Android software, should it break or decrease in efficiency you don't throw away something that was 800$.

There are a few good flagships I've seen. (namely most of Huawei) but there are also bad examples like all of Samsung.

If you ever had or know someone who had a J series you can easily tell those are less prown to issues and breaking compared to the S series.