Yes they are mandatory. If all other methods are a total waste of time and you can circumvent a risky, attention oriented, skill based activity by pressing a button, with no tradeoffs whatsoever; then yes that button is mandatory.
You can argue, if you want, that it’s good that ship landing has been reduced to a button press and that none of the previously built landing mechanics matter anymore; that’s a discussion we can have. What you can’t do, is handwave away the implications of new play mechanics with a “don’t like it don’t use it” rhetorical dodge. That’s not how games work, that’s not how rules changes to games work, and it’s certainly not how the impact of something like “press E to land” is going to shake out in Elite Dangerous.