linked_list

Why would a government use cryptocurrencies though? You only need that if you have no single source of truth. For a government digital banking is enough and way cheaper. Unless by crypto you just mean cryptographically signed transaction logs or something.

If you base64 encode an ascii string it gets 33% longer

The URL spec already takes care of a lot of this, for example /shopping/shirts?color=blue&size=M&page=3 or /articles/my-article-title#preface

JS does have features for editing the history, but it's a trade-off of not polluting the history too much while still letting the user navigate back and forth

Because a hash is by definition a one-way mapping, so then you'd have to keep a map of the reverse mapping hash -> state, which obviously gets impractical with state such as page index or search terms. Better just make two-way "compression" mapping