Python will take you a long way, but its ceiling (both typical and absolute) is far lower than the likes of Go and Rust. For typical implementations, the difference may be a factor of ten. For careful implementations (of both), it can be a lot more than that.
Does the difference matter? You must decide that.
As for your dismissing SQLite: please justify why it’s a bad idea. Because I strongly disagree.
There are a myriad middle states in-between "frupid" (so frugal that it's stupid) and "Instagram scale".
Python requires much more hand-holding that many don't want to do for good reasons (I prefer to work on the product unimpeded and not feeling pride having the knowledge to babysit obsolete stacks carried by university nostalgia).
With Go, Rust, Zig, and a few others -- it's a single binary.
This is a post about keeping your infrastructure simple, so Instagram is not a good ceiling to pick. People do all kinds of hacks to scale Python before they hit Instagram levels
Does the difference matter? You must decide that.
As for your dismissing SQLite: please justify why it’s a bad idea. Because I strongly disagree.