Try to watch Portuguese TV on prime time, specially when soap operas or loved series are reaching their last episodes.

Quantity can be excessive, but a TV commercial break still guarantees N minutes of harmless unimportant content you can ignore. It only wastes time, and not always.

Instead, a computer ad costs you money for bandwidth, can be intrinsically annoying (e.g. playing sounds or manipulating the browser), and poses a direct risk of serious harm (malware, subscriptions, snooping/tracking, etc.).

I think the most egregious example is latter seasons of The Big Bang Theory clocking in at 16 minutes. That's ~50% ads.