Bonus: good tests can also serve as technical documentation.

Though I have to disagree with the notion that documentation is as important or more so than code.
Documentation is certainly near the top of the list and often undervalued. I’ve worked on a project where documentation was lacking and it was painful to say the least.
Without documentation, changing or adding features can be a nightmare. Investigating bugs and offering support is also very difficult. But without code, you have nothing. No product, no users, no value.

There are (inferior) substitutes for documentation: specialized team knowledge, general technical expertise. These alternative pools of knowledge can be leveraged to create and improve documentation incrementally.
There’s no replacement for the actual functionality of your applications.

Ditto on the no text part. That is an accessibility failure that’s way too widespread.
Sometimes I’m afraid to even push a button: does this delete my thing, or does it do some other irreversible change? Will I be able to tell what it did? Maybe it does something completely different, or maybe I’m lucky and it does in fact perform the action I’m looking for and which in my mind is a no-brainer to include?

And it’s infected interpersonal communication too - people peppering their messages with emojis, even professional communications. It not only looks goofy, but is either redundant (when people just add the emoji together with the word it’s meant to represent - such a bizarre practice) or, worse, ambiguous when the pictogram replaces the word and the recipient(s) can’t make out what it depicts.
The most fun is when it’s a mix - the message contains some emojis with accompanying translation, some without.

I don’t share the hate for flat design.
It’s cleaner than the others, simpler and less distracting. Easier on the eyes, too. It takes itself seriously and does so successfully imo (nice try, aero). It feels professional in a way all the previous eras don’t - they seem almost child-like by comparison.

Modern design cultivates recognizable interactions by following conventions and common design language instead of goofy icons and high contrast colors. To me, modern software interfaces look like tools; the further you go back in time, the more they look like toys.

Old designs can be charming if executed well and in the right context. But I’m glad most things don’t look like they did 30 years ago.

I’m guessing many people associate older designs with the era they belonged to and the internet culture at the time. Perhaps rosy memories of younger days. Contrasting that with the overbearing corporate atmosphere of today and a general sense of a lack of authenticity in digital spaces everywhere, it’s not unreasonable to see flat design as sterile and soulless. But to me it just looks sleek and efficient.
I used to spend hours trying to customize UIs to my liking, nowadays pretty much everything just looks good out of the box.

The one major gripe I have is with the tendency of modern designs to hide interactions behind deeply nested menu hopping. That one feels like an over-correction from the excessively cluttered menus of the past.
That and the fact that there’s way too many “settings” sections and you can never figure out which one has the thing you’re looking for.

P S. The picture did flat design dirty by putting it on white background - we’re living in the era of dark mode!