The way some people put their points across in this thread is totally bonkers. And the way they attempt to discredit others is, at best, disingenuous. From both sides may I add!
For the record - I'm fully jabbed including booster, and think getting the vaccine is a no-brainer. But I wouldn't be in favour of mandatory vaccines.
A few things I'd like to comment on (in a civil way, hopefully!):
Assuming you meant January 2021 (there was no serious information around vaccines in 2020, let alone expectations), there was hope that a vaccine would prevent transmission but the main goal of the vaccine was to stop serious disease. There was some expectation (JVT mentioned in one of the pressers) that a vaccine would somewhat reduce transmission (reduce, not prevent 100%) based on our previous experience with these kinds of viruses (Flu, SARS, etc...). It was only when we had further results from trials and studies that showed definitively that it reduces transmission (even the AZ vaccines against Delta reduce it by 50% or so, which is still significant).
Again assuming January 2021 was meant - this was the working theory based on the Alpha (Kent) variant. It showed significant protection against transmission and serious illness (neither 100%). We didn't have any data on how long this would last for so any numbers were guesswork. Then Delta hit, which as we know is more dangerous and more infectious and this changed the goalposts, including requiring a booster.
However there is no-one credible suggesting we will need 3 doses per annum. Yes, some people have had 3 doses this year but this is because this is a very common pattern in distributing vaccines - based on how the immune system works. The idea is that the final "booster" dose gives a longer lasting, higher level of immunity. It still might not work, and we may need a 4th or 5th jab, we simply don't know. But this is how vaccines work in general - look at this tweet from someone who worked on the vaccines:
Someone from Pfizer has said that there are Delta specific versions available but they aren't needed yet (and haven't been through trials I believe?). The belief is that the booster will provide the level of cover required. It's not about changing the "recipe", it's about exposure and how your body builds immunity based on that exposure.
If more people were vaccinated, then the infections would still happen but it is extremely unlikely that infections will rise - in fact it is much more likely that they will go down. Especially once boosters have been administered. Why do you think infections would still rise when more people get vaccinated? Check out this chart -
https://twitter.com/sailorrooscout/status/1462444715144527876
Would you believe it if the information came from a Dr. at James Cook? This blog has been running throughout the pandemic and offers a great first-hand account of how things currently are playing out -
https://www.nomoresurgeons.com
Also the link you provide suggests that the majority of people admitted to hospital with Covid are vaccinated. I believe that is true, simply because the vast majority of people are vaccinated. I imagine the per 100k rate of vaccinated vs unvaccinated tells a different story. However, the original article was talking about ICU, not admittance. For someone to end up in ICU they must be quite poorly and fortunately the vaccinated people tend to get better quicker. The remaining unvaccinated are the ones that end up in ICU. Even then, a large proportion of the deaths are in vaccinated people as they tend to be the older people who don't make it to ICU, but it is the unvaccinated people (in their 20s, 30s, 40s) that are taking up valuable space in ICUs.
That was the understanding and expectation at the time, and then Delta arrived. Things change and we have to adapt, hopefully this time we will fare better!
Because the evidence shows the booster performs very well against Delta (transmission and against illness) and has already been through all of the trials etc... We would have to jab everyone again with the "new" vaccine, which would raise its own questions (plus it needs to go through all the trials etc first).
Our understanding of how vaccines and immune systems work suggest that (hopefully) we will have a longer lasting immunity from the booster than the previous 2 doses - this is how it works with other diseases/vaccines. Maybe we'll need a 4th, or indeed an altered vaccine - but at the moment this is the hope.