#2 can be an issue the opposite way as well, such as manufactured delays. Think of a modal window that pops-up after you've been on a site for 5 seconds and are just about to click a link, but instead click the modal. Or you begin reading, are 2 sentences in, and the modal pops up. When this happens, I close the page. It's so frustrating.

They consider app functionality and features, or look-and-feel and design, but they ignore UI (or don’t know what good UI is).

Like you described, even a simple search bar requires careful thought and experimentation to get right.

Another issue is UI libraries. People plug these in thinking they solve everything but in reality they only get you so far.

Generally speaking I want instant response especially on native apps, but I agree with all the examples you gave especially when it has something to do with Internet. I actually want consistent rendering time across the site rather than fastest possible page view every time.

It’s good for a UI to be immediately responsive to user actions, as long as the response matches the user’s intent. So it’s not the responsiveness that is the problem, but the response not matching the user’s expectations.

Otherwise, snappy interfaces are kinda nice.

I've recently been polishing up [1] for commercial release. It's a product that serves a real need for a niche community, and it's one that I built and use every day based on my own experiences for what I need as a member of that community, so I have even more reason than usual up get it right.

Truly instant responsiveness means putting the data as close and as hot to the end user as physically possible, to the point I wrote and tweaked my own trie implementation to get it just right. And even there with some of the new commercial features I'm starting to run up against ever so slightly noticeable input lag, and it really makes the whole experience feel clunkier than it should. Considering adding a 50ms denounce just to hide my shame...

[1]: https://github.com/hiandrewquinn/tsk

Easy fixes: • Search: add `?instant=0` or `debounce=300` to the URL (works on most Algolia & Elasticsearch front-ends). • Hover menus: enable “Reduce motion” in OS settings; many CSS media queries will swap to click-only. • Global: uBlock Origin’s `:has(:hover)` filter nukes 90 % of hover pop-ups.

If you build UIs, ship a 150 ms debounce by default—fast enough to feel alive, slow enough to respect human rhythm.

I bake that delay into every demo on my AI image tool: type a prompt, nothing flashes until you stop—then FLUX Kontext renders in 2.3 s flat. Try the no-jitter editor at https://flux-kontext.io