Confident, direct writing.

Be direct. Respect your reader’s time and interest.
Use qualifying words and statements sparingly.

With that in mind, let’s take a look at this little sentence…
Nearly all development and construction, in the strictest sense, is not fully sustainable.

“Nearly all”, “in the strictest sense”, and “fully” distract from the sentence’s core message: ‘Most development and construction is not sustainable.’

The idea of “Nearly all…” can be expressed just as well by “Most…” in less space.
“…in the strictest sense…” confuses the sentence. Better to define sustainability elsewhere.
“…fully sustainable.” is redundant. Something is either sustainable or it’s not. There is no half-way point.

It’s better to cut out the fluff, make one confident statement, and then elaborate elsewhere. Cramming too much into one sentence weighs down its meaning and trips up the reader.