This line is very misleading, as YTTV makes it sound like their customers will come out ahead with the $10 discount + $5 for Peacock while still having access to the same content. Peacock only replaces most broadcast prime time shows available next day (The Blacklist one week), a limited selection of shows next day from their cable channels, Sunday Night Football, some EPL, WWE, and coverage of a few other minor sports. You won't get any of their cable news content (other than highlight clips), your local NBC affiliate, and, well, pretty much everything else. And of course you can't record and watch without commercials unless you pay $10/mo.
It really depends on what you watch whether that would be an adequate replacement.