Why do we need the GTAG Init, especially on every page?
What is the GTAG?
According to https://developers.google.com/tag-platform/gtagjs , the benefits of using the gtag are:
“The best way to measure conversions and optimize the value of your Google marketing investment is to place tags on every page of your site. By implementing the Google tag across your site, you gain access to the following benefits:
Future-proof conversion measurement. Benefit from the latest features and integrations as they become available so that you are better equipped to continue measuring conversions accurately if changes occur.
Codeless tag management. Turn on measurement features within Google products without having to manually change the tags on your page.
Faster and easier integration. Streamlined, simpler implementation and integration with other Google products, such as Analytics and Google Ads.
More accurate conversion measurement. The Google tag helps you achieve more accurate conversion measurement when cookies are not available and recover conversions not observed today due to industry factors. “
Google specifically advises to use the tag on every page for the following reasons:
Short answer: you need the tag for the audiences in Google Ads. Not doing so could result in the audiences there being deleted or the values for some/many variables being nullified.
Long answer: but you don't know for sure. The Google Library is loaded via the tag, but it is a black box in itself. Our devs are trying to find out exactly how the tag works, can it be implemented completely on the server side and what consequences that would entail. The advice that you should use it everywhere is no longer a technical requirement, but it is probably still essential so that remarketing still works and the audience set-ups are not distorted.
Possible workarounds for not using the GTAG Init on every page are included in this forum on Stack Overflow: https://stackoverflow.com/questions/63411952/prevent-gtag-global-site-tag-from-tracking-initial-page-load