There seems to be an attitude, completely unspoken, that as long as someone is doing what they consider to be improving accessibility, then that is what is important.
There is nothing wrong, as such, with the attitude above. It is indeed a noble thing, to try to go beyond what is merely required, and to enhance accessibility in the many ways that did not form part of the final specifications. But the problem is that it encourages a much worse attitude to develop: that, because they are going to great effort to improve accessibility in one area, that they should be entitled to ignore their failings in another area.
From the point of view of a disabled person, this could be rephrased as: "Be greatful, that you have got what we have given you. You are lucky that you got anything at all, and if what we have given is not enough, then too bad".
Put another way; for a person who needs for a certain accessibility feature to be met, then, not having that feature - because some other feature is provided instead - is exactly the same as if that feature is not provided because they didn't care about accessibility at all. Exactly the same as if there is no accessibility at all; because, for them, there isn't any accessibility at all.
Accessibility is a hard problem. Even if you follow all recommendations, there will still be millions of people who would be unable to use your website due to a disability that they have. But you are not being asked to ensure that everyone can use your website, regardless of the expense and difficulty. You are only being asked to do what experts have found to be simple, reasonable, practical things that can improve accessibility for a large number of people, and in particular without compromising accessibility for other people (disabled or not). These are very modest recommendations, to the point that you really should have already been doing them anyway. As experts find more ways to improve accessibility for those who currently find the web to be inaccessible, and which are also simple, reasonable and practical, then these will be included in the recommendations of the future. And even before that, you can use them, if you meet all of your other obligations as well.
There is a reason that we have standards, and it is to avoid exactly the attitudes above. By following the standards, as your minimum, you are making your website accessible to those who it is known that it can be made accessible to; that it is known can be made accessible for reasonable effort and cost; that it is known will not impede the accessibility of others. You are welcome, and encouraged, to attempt to improve accessibility beyond the standards; but never, ever, instead of the standards.
Because if it were up to each individual to decide to support only the accessibility techniques that they choose, then most, unfortunately, would settle on "none at all".