In practice, what is the distinction between ESTA and visas?

I am one of those people on this site who almost always prefixes my answers to ESTA questions with "ESTA is not a visa. Your entry to the US is governed by the Visa Waiver Program".

The reason I do this is that questioners are often confused. They say "I read that I can only stay 90 days on an ESTA, but my ESTA say it is valid for three years." Or "If I drive to Canada and come back, do I need to get a new ESTA?".

So my intention is to direct people to look up the rules of the VWP, which usually tell them what they want to know. I also don't want to be one of the people perpetuating the mistake, so I always want to be saying "VWP will allow you to stay 90 days" rather than "ESTA will allow you to stay 90 days". If people learn "you can stay 90 days with an ESTA", and then find that with you can drive to the US without an ESTA, they ask "so how long can I stay then?". If they learn that VWP rules apply to both, they aren't confused.

My other reason for saying "ESTA is not a visa" is that is how the US sees it, and the US gets to decide. Correct terminology is important when you are dealing with legal issues. Calling it a visa is going to confuse people, especially if they eventually read official sites that call it something else. If the US asks if you have held a visa before, they do not want ESTA holders to answer "yes".

For all intents and purposes, ESTA is just what the US calls their e-visa concept.

Like other e-visas, it is somewhat more burdensome on travelers than traditional visa freedom, but quite a bit less burdensome than a traditional visa-in-advance.

They reason why they don't call it an e-visa is partly historical (it was one of the first such programs, so there was no established terminology to follow when they started it), and partly diplomatic (in a tacit understanding with other government that if they don't call it a visa, it doesn't need to upset existing reciprocal visa-freedom arrangements).

If an ESTA were a visa, the US would be in violation of reciprocal agreements on visa-free travel. So they say an ESTA is not a visa, and since the ESTA is an American legal concept their voice is significant. Other states are not calling them out on the inconsistencies. – o.m.

The list of similarities you posted has little meaning, as you need to do the first three things too when you want a credit card, or many other things.
However, you are right that in practice, the difference is meaningless for the vast majority of users.

The purpose of ESTA (='Electronic System for Travel Authorization') is to check if you are eligible to travel without a visa. Your input at that time is not verified, so you could type in whatever you want (the same is true for eVisa though).
The USA has no eVisa, and all other Visa require a lot more effort and answers, nearly always with a personal interview. The cost is also significantly higher.

All arriving travelers have to answer questions they are asked, that does not depend on ESTA, Visa, or even Citizenship. The USCIS officers have the right and duty to verify that you are who you claim to be, and that your intended stay is matching the limits and regulations. You can't take the questioning as a reason that ESTA and Visa are the same, as all travelers are subject to questioning (and eVisas in other countries are not any difference).

If your question was serious, that should point out the major difference; if your question was rhetoric and a ramble about the US milking you for money with a fake name - you are probably right, but think about how you would set up a better system; it would be interesting if you find a way to do it for free, without jeopardizing the secutiry.