A lot of the problem is that "reasonable ratio" and "everyone who wanted" are not the same number. The number I think of for reasonable ratio is 4 out of 5. Vaccination stalled well before that.
It will get only more difficult, in the early phases of the vaccine rollout, with patience and improved logistics, the ratio of vaccinated people improved rapidly. But what can they do next? Now comes the "stick", they will introduce more and more hurdles for the unvaccinated, but that takes time, causes resistance, and it will not increase the numbers fast enough.
All the while the variants are coming, and the existing vaccines do not show the same protection against the new variants, so there is a chance that the cycle will just continue with new variants, and new vaccines, new variants...