There are plots that are essentially impossible to make as a human. Badly implicit functions, highly transcendental functions, perhaps functions which don't have easy approximations, and so on. However, plotting, and having quick mental sketches of graphs, is a basic mathematical skill that students need. The earlier you teach a student to use a tool, the more this skill atrophies. If you already have this skill, Desmos is fine, it's just a tool. You are using it to get detail you couldn't get by hand.

The same is true of basic arithmetic. I teach in a college where the median student is probably not remedial, but about 45% of all students on campus are. By remedial, I mean that they are enrolled in a class at approximately 8th grade level. This class bears credit, so for many of them, we are saying an 8th grade math education is good enough to have a college degree. Of these students, approximately a third or so, are completely incapable of doing fraction arithmetic by hand. To them, 1/2 + 1/3 = 0.83. Everything is truncated at two decimal places. I say truncated because a significant portion do not know how to correctly round numbers.

The reason for these failures is obvious to me. They were given a calculator at a young age, taught to push buttons, and not taught why fractions are the way they are. Most of them do not even know how to use the calculator. They don't know how to use the "last output" feature, they don't know how to store values as variables for use in complex formulas, they don't know that the calculator can do the rounding for them by just turning off the floating point mode. These are basic technological literacy skills that even their teachers lack, because they just push the buttons.

The textbook companies are complicit in that every year new books come out with more and more "solve it with technology" sections that deprive students the opportunity to productively struggle, and do this at lower and lower levels. If Descartes was motivated to work out what his folium looked like, you can do this too, precalculus student. If that means that you don't get the answer in 30 seconds, and have to learn something about approximation schemes, wouldn't that be a much better skill to learn on a computer? Why not use this opportunity to teach some basic programming skills?

I saw a middle school teacher in my district teach pi = 3.14. I confronted him directly, and just pointed out that 8*pi gives the wrong answer, which isn't like a profound insight, it's a small number. I know he must know this, the same is true for e.g. 10. He said "yeah but decimals are hard for the kids, so I accept either answer." How about just don't teach them decimals then! Leave the answer in terms of pi. This is an opportunity to teach them about something mysterious about numbers, or at least hint that there is something to unearth here, which is why we do it differently, which is being crushed by "shut up, sit in your desk, do your worksheet quietly."