Can you share your computer specs and what browser you're using?
It's buttery smooth on both my Windows desktop and Mac laptop, though both are relatively new.
On my 5+ year old 1.1GHz MacBook it's still entirely usable. Dragging windows around isn't entirely fluid, but it's not that bad for such an underpowered machine.
I'm on a 2019 16" MBP 2.6GHz i7 with a 5300M. This machine isn't a powerhouse, but it can drive 1080p240Hz + 1440p144Hz buttery smooth for a million Firefox tabs and a couple IntelliJ projects (if everything's all indexed...). On this site, I get like 10fps while doing things, clicking, moving around, etc. It doesn't even look like motion. I threw it into Firefox's profiler and it has consistent "janks" between 100ms to over 200ms. No thanks.
Perhaps we have different ideas of what constitutes "buttery smooth". I find the performance usable but sluggish. I think many people have become accustomed to this kind of performance though. Regardless, I find the design of the UI quite appealing.
Yes, I have a recent and powerful GPU with hardware acceleration enabled. I also tried this on my Windows box (i7-9700k, Nvidia GTX 1070), and if anything, it performs a little worse than my Linux box. It's definitely usable. I just have a low tolerance for sluggish software.
Just another data point here: I'm running a relatively high-end workstation on Linux/Fedora 36, and it is quite smooth in Chrome but somewhat sluggish in Firefox.
I worked on a proprietary trading app using flutter for mobile and we had zero issues whilst rendering both ticker prices and charts in real time. How is desktop so different?
5950X, 32 gigs of RAM, Win10, Firefox 98, 3080Ti (if it's GPU accelerated, I didn't look) and it's super jittery for me. It's usable, but it's not smooth at all. Dragging windows around is pretty bad.
I'm on a Framework running Arch with a 165 Hz external monitor, using Firefox, and it feels sluggish to me. It's usable, but feels like the performance I'd expect from a website. For example, grabbing a window and thrashing it around, it noticeably lags behind my mouse cursor. Resizing a window from the top is pretty bumpy. It lags behind the mouse and the repainting stutters.
You should try brave or chrome it's pretty smooth for me on a 5 year old Ryzen 1 system with 32GB memory. I don't even remember what my AMD card is, it was a mediocre card 5 years ago whatever it is.
Probably a case of having hardware acceleration turned off in the bowser, which at least for me is necessary due to issues with casting chrome windows in things like discord.
It's also perfectly smooth for me on Firefox on Linux, although my hardware is pretty performant (Ryzen 9 5900X), although normally Firefox detracts significantly from performance.
Current machine: Edge (closest thing to Chrome that i have apart from Firefox) or Firefox, Ryzen 5 1600, RX570.
The performance is passable for a graphically intensive application but entirely unacceptable for a desktop environment of any kind. In addition, it seems like it is a bit worse optimized on Firefox than it is on Chromium based browsers.
Opening 1 window and dragging it around leads to ~25% of the GPU usage (albeit i power limited mine to 50% of the total capacity), which feels insane when you consider that games running at 60 FPS use maybe ~50%. Opening up more windows, anywhere between 5-10 and dragging them around yields a similar load to rendering tens if not hundreds of thousands of polygons on screen.
Thus, i have to agree with the folks that say that this is entirely unacceptable as a desktop environment for any device, apart from when you are inclined to waste your hardware resources for no good reason. Admittedly, Flutter is better suited for this than it is for web development (in which it can be downright hostile and cause accessibility issues) and if nothing else the UI looks good, but personally that's not something that i care about.
In summary: i don't think that this would ever be an acceptable desktop environment, especially for devices that are running on battery power. Its resource usage would cripple any graphically intensive tasks in the background, unless you have really powerful hardware, which isn't the case for much of the world. Then again, in my eyes the perfect DE is somewhere along the lines of XFCE/LXDE/LxQt, so YMMV.
Edit: tested it out on my notebook as well, which has a N4000 Celeron and Intel UHD 600 integrated graphics. Even opening 1 window lagged everything considerably (on Firefox) and i have to guess that the FPS was somewhere between 10-20.
So, once again: unacceptable as a desktop environment, even with any given browser overhead. Of course, being able to run software like this in the browser reflects positively upon its portability, if nothing else, which is cool to see.
I wonder where we could get benchmarks that compare the low level rendering performance of the web vs native targets per platform. Having something like that would probably be immensely useful to be able to reason about the differences between them.
On both my Windows laptop (Ryzen 7 + 1080Ti) and Windows Desktop (Ryzen 9 + dual RX 5700 XT) machines, it is really slow. Dragging windows is unbearable and the other apps are quite laggy (such as switching views in the "media" app). Both have hardware acceleration enabled.
On my Windows workstation with a Ryzen 5800X and an RTX 3080, it is a stuttery mess on Firefox. Dragging windows happens at maybe 10 FPS, and there's half a second of input latency on everything.
Can you share your computer specs and what browser you're using?
It's buttery smooth on both my Windows desktop and Mac laptop, though both are relatively new.
On my 5+ year old 1.1GHz MacBook it's still entirely usable. Dragging windows around isn't entirely fluid, but it's not that bad for such an underpowered machine.