A lot of the "lets just hire lots of grunts" mentality implies someone is going to do a lot of the other work - talking to users, documenting requirements, creating well specified dev tickets, implement SDLC tooling, integrate with SRE, create guard rails, do documentation, testing, code reviews, style guides, etc.

Which is to say - most of the stuff you expect a senior to just be able to do as part of their job while also writing better code.

A large enough org may be able to offload much of those tasks to dedicated people and/or teams. Similarly a mature enough platform could have lots of BAU dev that can go to grunts because the basic infrastructure already exists and the workflows are well known with good tooling.

So it really depends on organizational size & maturity if its a good trade.