The other angle is the majority of Devs are just… Not good…
A good Dev in the situation you mention will design the solution needed now not the one you hope for later.
I’m saying this as someone who has been mired in scope creep and over engineering solutions many times in my life because “what if 5000 people need to use it at once?!”
In most cases all you need is a database, a single thread and a simple API. Build it and then as the problems come grow with them. Try to take into account issues of scale but realize you can’t and shouldn’t solve every scenario because there are too many variables which may never exist.