They kind of need to be there anyway, physically maintaining servers turns out to be a miniscule part of the whole maintenance. If you really care about uptime you still need people on-call who can intervene as necessary.
Once you have on-premises you need people that know switches, routers, rackmount server, hardware, virtualization, etc, plus keeping all of that properly maintained (security patches, IaC, periodic updates, analyzing performance, making sure it's properly architected, etc).
I often see people saying it's the same cost or less but it's really not. Unless you have no idea what you should be doing.
Virtualization, IaC, analyzing performance, right architecture etc is all for later, when you've grown enough to need that.
Yeah, I think it might be a different perspective about when that all should be done.
I tend to do that right from the beginning because I often see it snowball later on and nobody ever fixes it or does it "properly" (in my opinion, possibly not the right one).
But that's a good point, no doubt.