Data caps are simply false advertising - if your infrastructure can only handle X Tb/s then sell lower client speeds or implement some clever QoS.

There are plenty of users for whom 1.5TB is quite or very restrictive - multi member households, video/photo editors working with raw data, scientists working with raw data, flatpak users with Nvidia GPU or people that selfhost their data or do frequent backups etc.

With the popularity of WFH and our dependence on online services the internet is virtually as vital as water or electricity, and you wouldn’t want to be restricted to having no electricity until the end of the month just because you used the angle grinder for a few afternoons.