It gets even more confusing! If you're on the "Premium" plans (i.e the the old standard "Google One" plans) and upgrade to >=5TB storage, your "Premium" plan starts including all the features of "Google AI Pro".
Tip: If you do annual billing for "Premium (5 TB)", you end up paying $21/month for 5TB of storage and the same AI features of "Google AI pro (2TB)"; which is only $1/month more than doing "Google AI Pro (2 TB)" (which only has monthly billing)
Tip: If you do annual billing for "Premium (5 TB)", you end up paying $21/month for 5TB of storage and the same AI features of "Google AI pro (2TB)"; which is only $1/month more than doing "Google AI Pro (2 TB)" (which only has monthly billing)