The firehose is real, and it is exhausting
Sign up for raw RFP feeds and you will get hundreds of notifications a week, the overwhelming majority irrelevant to your business. The promise of "never miss an RFP" turns into a second inbox you have to triage, and the cost of that triage is real — every minute spent filtering is a minute not spent estimating or building.
Generic alert services match on keywords alone. They do not understand your trade, your geography, or your eligibility, so they cannot tell the difference between an RFP you should drop everything for and one you would never bid on.