Yes, that is why I said enterprise scale. Pricing for personal stuff is pretty terrible, although it is reasonable in some ways.
I find AWS prices to be very reasonable, but it is much different than going race to the bottom deal hunting on hetzner. That's definitely where you want to go deal hunting, but it isn't suitable for a lot of enterprise applications.
With the bigger CSPs, you really have to take care of the billing yourself to get the best value. Last year, my team was able to cut our client's cloud bill by 85% while improving service. Kind of unfair - AWS will happily take your money to do stuff incorrectly. They have business units at AWS around customer success that aims to help cut costs, but I can kind of tell they aren't a priority at the company compared to account execs. Pretty normal for this business, unfortunately.
Yes, vendor lock in is always a concern around AWS. I am of 2 minds about this - the real trade off with on demand resources is cost as AWS has to essentially have hot instances ready for customers, which cost them more to run. So it definitely makes sense to have these billing options that help them save operational overhead and then pass the savings on to their customers.
But it is a fine line. What should be AWS responsibility and what should be the customers? Amazon's whole deal is trying to step over it it ways that will ultimately be monopolistic. Personally, I am much more concerned with the egress costs, which is their true and much sneakier vendor lock in trap.
To me, the only answer is government regulation. We should treat cloud resources as a utility and regulate it as such to make sure that the large players don't abuse their monopoly on compute power and servers. Instead, the government's answer has been to do away with net neutrality, which really only makes them more powerful because they still have a monopoly on the physical resources. This is one of the reasons why I have become self hosted for my own personal technology - but for work there are a lot of benefits to just shutting up and working with a monopoly that at least has to try to drive down costs at some level to prevent regulatory action.
These services only make sense at scale and with large projects that need a ton of planning everyday. AWS will take the little people's money if they are willing to give it, but they aren't truly interested in their business.