My impression, wholly prone to error, is that despite centuries of Roman occupation, after the Anglo-Saxon invasions, Latin virtually became a dead language in Britain.
Other parts of the Roman Empire — such as Gaul (France), Hispania (Spain and Portugal), the Italian Peninsula and Dacia — also saw the retreat of the Romans and were invaded by tribes in their wake, yet the 'Romance' languages of all these countries are in important ways modern versions of Latin.
What made the British experience so different?