Mozilla believes that neither @apple nor @google should be able to grant their own browsers exclusive privileges on their respective operating systems. OWA strongly supports this position.
We encourage you to read Mozilla’s full response here:
https://assets.publishing.service.gov.uk/media/63e22fa1d3bf7f172f6ce872/Mozilla.pdf
For example in the Mozilla Web Developer Needs Assessment 2020 Survey when asked which browser caused the most issues (ignoring the now deprecated Internet Explorer), developers overwhelmingly picked Safari as the browser causing the most issues.