I love this line of thinking, it's how old companies I worked with developed entire rest APIs using only AWS Lambda and after sinking tens of millions into it they abandoned it :)
But this is the classic engineering mistake in how they communicate. They replace “why should we do this” with “we can’t do this” and it leads to the same old stupid conversations with eng who are probably pretty smart but have no self awareness of their communication failures
CAN IT BE DONE? OH YEAH!