This does not match my experience, I use gridcraft (excel), vectorcraft (illustrator) often; they work fine.

It's ~100MiB each, installs in seconds; I can point my agent at the github repo and it will be able to run it and control the apps; e.g. look at how excel spreadsheets actually render and adjust the layout.

I'm not a power user, but for my particular use cases artcraft apps are better than the original counterparts (install-size + agent control).

I've been using filmcraft for video editing and I've had no issues.

Agent does not feel discomfort from laggy UI so your point is moot.