w11 started with no fast travel across odeeper/High Seas.
I have no hard data on this, but most of the supposed "Travelling Merchants" quit the game before ever building a Knarr*. Developers eventually relented and allowed Charter Stone travel across oceans.
*This sounds extremely harsh, especially considering back then Knarr wasn't gated behind having access to a deep mine level (Sunstone.) I'm also probably parroting people like DonVeID. However it's not a stretch to assume that the "locality good, easy fast travel bad" -people are a loud minority who never bothered to actually engage with the playstyle, even after rest of the game was more or less gutted to accommodate it.
To steelman their argument to the maximum, maybe the "travelling merchant" -period coincided with some other patches that drove away the potential merchant players. Even so, I can't imagine that sailing Knarr for hours on end would be an engaging gameplay experience. Also citing this chart, it would probably take far less than 2 months to create a script that can more or less automatically operate ferry across two ports. (Adjust the chart's five years to one year of estimated world length and go from one hour to 5 hours of daily automated sailing.)