Twitter's 140 character constraint wasn't artificial in the beginning. Twitter was meant to be used through SMS and that was the maximum message size.
For as long as I can remember, Twitter allowed 140 Unicode characters, whereas SMS limits messages to 140 bytes.
01234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789
(Desktop with Vivaldi)
The unicode extensions for SMS only allow 70 UCS-2 code points. So from the perspective of ASCII, SMS can too big to fit into a tweet, and from the perspective of Unicode a tweet can be too big to fit into SMS.
Tweets to me look like a product manager liked the constrained aspect of SMS, but didn't dig hard into the details.
In aggregate, having the limit is a cost decision. We absolutely can and do send messages longer than 140 characters. But we make a best effort to limit it to a single SMS segment. If some are over, oh well.
interestingly Europe was all over SMS messaging in the 00s, but it didn't really become popular in the US until this decade, when carriers starting bundling unlimited SMS in plans.
-Edit- Okay, I was wrong. Forgot to think before I posted.
Source : own an MVNO
https://en.wikipedia.org/wiki/Mobile_virtual_network_operato...