In a world where paper documents increasingly get replaced by electronic records, long term access to the data becomes critical. This is especially the case for legal contracts and government documents which stay valid and relevant over decades, or even centuries.

Like paper and pens have been available from multiple vendors, and not just one single source, document file formats and the applications creating these file formats need to be supported by and available from multiple vendors. This guarantees long-term access to data, even if companies disappear, change their strategies or dramatically raise their prices. 

Open standards that are equally accessible and do not favor one particular vendor, help maintain a diverse ecosystem of vendors. This as well causes competitive pricing, thus ensuring the best use of money from investors or tax payers.

Open standards also lower the barrier of entry, allowing new companies to join the ecosystem. For example, the SQL standard for relational databases allowed the emergence of various implementations including free open source and very specialized high-end database management systems. As long as only standard SQL features are used, database management systems can be exchanged without much effort. Vendor lock-in only happens based on special features not included in the SQL standard. Thus, vendor lock-in becomes a voluntary choice, not a mandatory one.

In the case of public documents provided by governments to their citizens, it is also important that no citizens, or at least as few as possible, get excluded from data access. For example, nobody should be forced to buy software from one specific vendor or for one specific operating system platform. Public data should be accessible to citizens independent off their income and their physical abilities.