[Bhel]

In which cases are such keyboards necessary?

I use a $3 one (which I bought to replace the one I used for over a decade) and I've never had such issues. I use this keyboard for coding and gaming, not just for common tasks which require low performance.

[garrettgrimsley]

I use a Model M and sometimes encounter ghosting. Some types of gaming are worse than others. For example, while playing RTS or MOBA I do not encounter ghosting while playing FPS I encounter it on a regular basis.

This is because in RTS and MOBA while you might be rapidly hitting your keys you should be hitting them in succession, not simultaneously! In the FPS on the other hand you might be trying to walk forward and right while crouching and reloading, which requires four keys to do. This would cause problems for my keyboard.

Programming is more like the RTS than the FPS in this respect. You may be hitting a lot of keys, but the combinations are more likely to involve modifiers such as CTRL, ALT, or shift rather than a combination of letters.

[Bhel]

Makes sense. I barely play FPSs anymore, but I can imagine the scenarios that you describe, and after testing the keyboard on that site, it's clear that my actions would fail on such scenarios.

So, I take it that anti-ghosting measures are primarily meant for gaming keyboards.