Full Idea
In modern mathematics virtually all work is only up to isomorphism and no one cares what the numbers or points and lines 'really are'.
Clarification
'Isomorphism' is where all the models coincide in structure
Gist of Idea
Modern mathematics works up to isomorphism, and doesn't care what things 'really are'
Source
Shaughan Lavine (Understanding the Infinite [1994], VI.1)
Book Reference
Lavine,Shaughan: 'Understanding the Infinite' [Harvard 1994], p.157
A Reaction
At least that leaves the field open for philosophers, because we do care what things really are. So should everybody else, but there is no persuading some people.