Volkswagen has definitely been fined less than Google - they were fined about a billion. The difference is though that the EU wasn't really prepared for the Volkswagen fraud - there was no standing law setting enormous fines for companies engaged in an emissions fraud of that scale like there is for GDPR violations. Since the scandal they brought in legislation to prevent it in the future, including fines of up to €30,000 per car sold violating the emissions guidelines.

EU regulator powers operate with an honestly fairly limited scope based on the laws passed by parliament and the commission. There's no EPA like organisation with broad powers to persue companies for most forms of misbehaviour like there is in the US - that's left to the member states, with countries like Germany and Italy individually prosecuting Volkswagen executives for fraud.

The difference with GDPR and anti-trust violations is that the EU has been deliberately granted the power to exact severe fines on companies for each individual offence. If post-scandal Volkswagen had been caught falsifying emissions again and again (similiar to Google's repeated GDPR violations) they might have been hit with more and more fines of the severity that Google has.