Paid time off was designed around physical absence. When nobody is physically present anyway, the policy has to be enforced by behavior rather than by location.
Absence is no longer visible
In an office, an empty chair communicates that someone is away. Colleagues route around it automatically and without being told.
Remotely there is no equivalent signal. A message sent to someone on vacation looks identical to one sent to someone at their desk.
Companies compensate with calendar blocks, status indicators and automatic replies, all of which depend on the employee configuring them correctly before leaving.
Unlimited policies often reduce time taken
Policies without a fixed allowance remove the accrued balance an employee would otherwise feel entitled to spend. What replaces it is a judgment about what is acceptable.
Absent a number, people look at what colleagues take, and the cautious anchor low. The observed outcome in many companies is less time off, not more.
Minimum requirements, where the company mandates a floor, address this directly by restoring a number people can point to.
Time zones distribute holidays unevenly
A team spread across countries observes different public holidays. Work continues on days when part of the team is legally off, and vice versa.
This is usually manageable and occasionally not, when a deadline falls across a holiday that half the team observes and the other half has never heard of.
Shared calendars listing every region's holidays are a low-cost fix that most distributed companies adopt only after a scheduling failure.
Coverage has to be arranged deliberately
In an office, someone nearby usually picks up an urgent item. Distributed teams need a named person, because proximity no longer supplies a volunteer.
Handover documents before extended absence serve the same function as the conversation that would have happened at a desk.
Where this is skipped, the person on vacation is contacted, which converts their time off into partial availability and discourages the next person from disconnecting.
Disconnecting requires explicit permission
Employees judge the real policy by what senior people do. A manager who answers messages while away establishes that as the expectation regardless of what is written.
Some jurisdictions have legislated around after-hours contact, and rules on this vary by location and continue to change.
Inside a company, the effective rule is set by observed behavior. Where leaders visibly disappear and return, employees do too, and the policy functions as intended.