It depends on the landlord and type of place. A long-term lease comes with additional considerations for the landlord, mostly in terms of a long-term lease often requiring slightly different legals and a loss of optionality.

While I've had landlords that were not prepared for a long-term lease, I've never had an issue getting one anywhere I've rented. I've also had this work against me i.e. rents actually decreased halfway through the contract.

Because as soon as you sign that longer lease, the landlord will only ever do the absolute minimum repairs because you're stuck in that lease. We have been reporting our leaking roof for years...

It adds inflexibility with few benefits, and one doesn’t know that they’ll want to stay at any given place until they’ve lived there for a while.

I have never lived somewhere that allowed longer than a 14-month lease.