Sure, but by doing that they move under the above mentioned assumption that (fast) internet is always available to all the users, devs, etc.

AFAIK the last big push to get out of "it works on my machine" was the JVM which has become a bloated, inefficient mess that a vast chunk of the industry uses anyway, because most often it's deemed "good enough" and Java, Kotlin etc. devs are relatively easy to find and/or train compared to "native" development in say C/C++, Rust, etc.