@polotek I've done a few rescue missions for clients which turned into sort of "front-end ops" gigs, more or less just wrangling these toolchains sort of like how Kent describes here: https://kentcdodds.com/blog/tools-without-config
I've found that each team does need a subset of what these kits offer. There isn't always a clear cross-team overlap. Open-source doing it all is definitely why the kits are huge.
OTOH the bespoke shop-specific way really is costly to invest in. It can turn into a full-time support role.