The length distribution of tweets has shifted in response to raised character limits, but it's still the case that a disproportionate number of tweets use all the characters they're given.
A sample of tweets gathered in 2019Twitter stream 2019-05. Internet Archive. (2019-10-27). still exhibit a telltale spike approaching the character limit, but it is smaller than the tweet distribution from a decade earlier. The peak of the curve has also shifted leftwards, to 15 characters, due to a separate change in 2016 that excluded media attachments and certain at-mentions from the character count.
The most interesting feature of the above graph is unfortunately an artifact of the dataset — the massive spike at 105 characters can be blamed on a spambot network broadcasting identical copies of the same tweet when the dataset was collected.
A disproportionate number of my tweets are exactly 140 characters. I don't know whether that means I'm really good at Twitter or really bad. Sometimes it's the result of a too-long idea being meticulously edited down to size; sometimes it's purely chance. Either way, I find 140-character tweets oddly satisfying — and based on a large dataset of tweets, it looks like I'm not the only one.