You're not supposed to look for ending parentheses in Lisp; getting the right number of them is more or less your editor's job, and they are maximally stacked together like this: )))), as much as the given nesting and indentation permit. Given some (let ..., the closing parenthesis could be the third one in some ))))) sequence; you rarely care which one. If it's not matched in that specific ))))) sequence where you expect, then that's a problem.
)))) is like a ground symbol in a schematic:
(+5V
(+10V
(-10V
(INPUT3 ...))))
----- local "ground" for all the above
(different circuit)
That doesn’t seem very user-friendly. ;) Or at least that’s always my perception when programming Lisp.
As a side note, I believe that different people fundamentally have different programming languages that objectively suit them best, due to differences in their respective psychology and way of thinking and perceiving. It’s interesting to discuss trade-offs, but in the end there is no single truth about which language is better overall — it depends on the task and on the person. There’s no “one size fits all”. What’s valuable is to understand why a certain syntax or language might work better for certain people.
Mainly, you don't look at the parenthesis when reading; you look at that let and your eyes rely on indentation for structure.