For blocking presubmit checks, getting the fastest machine you can is probably reasonable. Otherwise, the advantage of the craptop approach is that it needs basically no infra work and gives an immediate impression of the site, and not CI, being slow.

If you’re willing to build some infra, there’s probably a lot more you can do—nightly slow-hardware runs come to mind immediately, browser devtools have a convincing builtin emulation of slow connections, a page displaying a graph of test runtime over time[1] isn’t hard to set up, etc.—but I don’t really have experience with that.

[1] See e.g. https://arewefastyet.com/win11/benchmarks/overview?numDays=3....

I kid you not a few jobs ago I found several race conditions in my code and tests by running them at the same time as a multi threaded openssl burn test. :)