This is not about taxing revenues instead of profits. This is about taxing EU-wide profits in EU countries proportional to the revenues generated in that country. At the moment, many big tech companies use bookkeeping tricks to make it look like all their profit is generated in, for example, Ireland, while the revenue is generated in other EU counties. Unfortunately, Ireland has special tax rates for these companies…
In all fairness, it's not just Ireland. Luxembourg and - partially - the Netherlands also participate and benefit from this.
This will get a lot worse before it gets better.