It seems as if the web has influenced the latest round of GUI designs, especially the 'flat' design trend which has clearly harmed usability when it comes to things like buttons. This is handled better by Android's material design guidelines, but it's still a regression.
The problem with this approach is that the web has no guidelines whatsoever, beyond user-agent defaults. So each and every site does their own thing (whether 'good' or 'bad') and Apple (+ Google, etc.) decides to cherry-pick what is 'popular' or thought to 'look good', seemingly without thinking through the impact on usability. Or, possibly worse, they have considered the usability impact but deem the tradeoff worthwhile.
The problem with this approach is that the web has no guidelines whatsoever, beyond user-agent defaults. So each and every site does their own thing (whether 'good' or 'bad') and Apple (+ Google, etc.) decides to cherry-pick what is 'popular' or thought to 'look good', seemingly without thinking through the impact on usability. Or, possibly worse, they have considered the usability impact but deem the tradeoff worthwhile.