1GB that grew to 7GB over about 4 years and then 15GB over another 5 years. And has been stuck at 15GB for about 13 years. https://lifetourer.com/gmail-and-storage-capacity-cmon-googl...

The limit used to cost a whole dollar of hard drive space (plus redundancy), sometimes more than that. If they kept that up with adjustment for inflation then 100GB would be the free tier today, not a $20/year tier.