I think you are missing the point of the article. I read it as "this desktop software could make use of serverless to provide me a re-encoded 4gb video file in seconds by doing 3000" tasks (provided my bandwidth could handle that). My gripe with that is the one of privacy (I do not want my data processed elsewhere).
Still I would not be opposed to such client-server(less) architecture being used where I could have slower devices seamlessly integrating with my personal server for faster processing of compute heavy tasks.
It's not that this hasn't been done before (thin clients anyone? Even X server model is exactly like that), but a similar approach could make a come back at some point.
For most people, uploading that 4gb file for cloud processing will take an hour. But re-encoding 2h of video with GPU acceleration only takes 15-20 minutes. So no matter how fast serverless is, it'll always need to wait for upload and download, which may be slower than all the computations combined.
As for X server, using it over the internet is a pain. It is optimized for a low latency connection, meaning the opposite of putting calculations in a cloud hundreds of ms of ping away.
Oh, I am not saying we are there yet as far as bandwidth is concerned, but even a 4G connection from a slow device like a phone is going to look better today. Uploading 4GiB file at 50Mbps will take less than 15 minutes, or 5 minutes at 150Mbps, and no phone would re-encode it in less than that. 5G goes up to 1Gbps, or 32s for a 4GiB file, and there's your case. Wouldn't you find it nice if your phone could do this in 30s without really burning like a stove as CPU usage spikes?
Again, we are not there yet, but we are not that far off either.
My mention of X was to highlight how this is just old technology within new constraints (move things that do not need small latency from the thin client onto the fast server), but how it's applied is going to make it or break it.
In that case, I agree. If we had WiFi-speed internet, Lambda would be amazing for mobile apps.
But my lived reality is that I have to go to the upper floor in my parent's house if I want to have 2G reception. And they only live a 10 minute drive from the town hall.
Still I would not be opposed to such client-server(less) architecture being used where I could have slower devices seamlessly integrating with my personal server for faster processing of compute heavy tasks.
It's not that this hasn't been done before (thin clients anyone? Even X server model is exactly like that), but a similar approach could make a come back at some point.