Why dates matter
Each policy line on a certificate shows an effective and expiration date. A holder reading the certificate after the expiration date learns nothing about whether the policy renewed. Mid-term cancellations are worse: the certificate still looks valid while the coverage is gone.
The renewal cycle
With a PDF certificate, every policy renewal means a new certificate for every holder — landlord, general contractors, clients, licensing. For a small business with three policies and a dozen holders, that is a few dozen certificates a year, each one a request to the agent.
The live alternative
A live certificate is a private link per holder. Opening it shows the current status of each coverage line with the time it was checked, the holder's own status (additional insured, waiver), and a PDF download. When a policy renews, cancels or is scheduled for cancellation, the page updates and the holder is told. You share it once.