This is not the web in which you can choose Safari, Mozilla or Chrom(e/ium) where these 3 programs all operate under the same web / http protocol.
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They can always upgrade to get access to newer features but the web is always the same. There are no two webs.
Could you point me to the global consensus ledger that Safari, Mozilla and Chrome maintain together? No? Then you're making a terribly foolish analogy.
I'm just giving an example where the different software for bitcoin is not the same as having different software for the web. Obviously there is no ledger as far as the web is concerned. The web is not a blockchain.