What happens if we never file a tax return for the duration of our work visa (3 years)? Is it possible to go back to our home country without any consequence or does the IRS pay special attention to resident aliens?

Will the IRS come after us or audit us, or will they more likely allow us to slip through the administrative cracks in their system because we are on work visas?

Please advise. Thank you.

Negative. The U.S. has reciprocity agreements with most western countries. Your own government would enforce the results of the tax audit.

Further, your company is required by law to withhols the required taxes from your salary. It's likely that failing to file the tax returns would only result in you forfeiting the tax refunds that would be due to you.