I understand that upgrading will remove the banner.
While not a "banner", I blame Apple and their "cleverly" worded "Updates available" Notifications for 'leading the way' to too many chances to mistakenly update something. Many apps have a setting for checking for an update "Once a week", which seems satisfactory to me. I also wonder if Apple's tightening security is making this harder for Devs.
And then there is the all-day, every-day, red dot on System Prefs telling me to enable two-factor authentication. Did that once. Fooled me once. Never again. I'm not running a business, this is my home, if the thief takes my hardware, not even 2FA will prevent losing my recipes and family pictures.
On my iPhone, I click "Not now" to the update offer. Then up pops the License agreement! WHY?! Finally I click "Disagree" and that seems to get the message cross.