High falutin' correctness doesn't go hand in hand with sentence length.
(Apparently, the longest sentence in an English language book is from Jonathan Coe’s novel The Rotter’s Club. Weighing in at just under 14,000 not-a-typo words, Coe's sentence handily beats James Joyce's mere <4,400 word-sentence in Ulysses. I confess I have read neither book, so if you have, here's a gold star! ⭐
With many possible single word sentences, no one book could win the award for the shortest.)
Yes, sentences with many words can be harder to write grammatically, with good style, than their brief counterparts.
Writers have to apply diamond-forming pressure and focus to keep readers from losing the point, but this handholding serves as a necessary part of craft.
Long sentences slow down pacing. Short sentences speed things up. Neither of these outcomes is wrong or bad or a technique to avoid.
Consider the humble walk.
Image: footprints
We can stroll through neighborhoods, meander through gardens, enjoy lazy Saturday rambles. Or, we could dash to the bus stop, sprint in a race, dart across a busy intersection.
All movements have a purpose. Our need determines the pace.
So it is for writing.
In my writing, I constantly struggle against overlong sentences. In my self-edits, one of the most important questions I use in sentence interrogation is: are you so long and complex you are slowing readers down in a way that does not serve the piece? About half the time, my honest answer is yes.
When the pacing seems off, whether that offness manifests as dull or frenetic writing, check your sentence variety. Construction matters — too many subject-verb, subject-verb, subject-verb constructions kill good narratives — but variety in length carries surprising weight.