People should just stop worrying about their Anki backlog. The truth is, every little bit you do helps, even just one card a day. That "backlog" is just telling you that you are falling short of perfection wrt. keeping the whole content of your deck securely memorized. You'll still be able to recall the bulk of it as long as you keep a reasonable routine.

As a fellow sufferer of same issues, I sympathize.

You are too hard on yourself though.

It is like a running race, when we are required to carry 50 Lb bags on our backs, while others are running freely.

At some point we need to accept and not worry too much!