Google Tag Manager review

No. One tag pasted into the site is simpler than a container built to manage many, and a layer you don't need is another place for things to go wrong. It earns its place at the second or third script (an ad pixel, a CRM snippet, a campaign conversion tag), because that's when every new measurement request becomes a developer request.

It can, and the scripts it loads usually matter more than the container itself. That's solvable, not a reason to avoid it. This site runs its tag container in a web worker instead of on the main thread, which took mobile performance from the middle of the range to the top without losing any tracking. If your tags hurt page speed, the fix is usually where they run, not whether you have them.

Silent errors. A mis-wired trigger can fire an event twice or not at all, and unlike a broken snippet, a bad tag doesn't visibly fail. It quietly produces wrong numbers, often for weeks. Test changes in preview mode before publishing, not after.

One person, deliberately. The failure mode is a container nobody owns, where every tool that needed tracking got bolted on by whoever was in a hurry that day, and three years later nobody can say what half the tags do or whether they're safe to remove. Name an owner, note what each tag is for, and audit it occasionally. That's most of what separates a useful container from a liability.