A mechanical component of any kind will have a lot more failure modes than something solid state. Granted an industrial use micro-switch will be a lot better than any kind of user interface button, but it will still be prone to having something stick the switch in or out of place, having the lever bent so you need to re-adjust etc. If you’re just using it at home and you’re not burning money if the fixture stops for a day - it doesn’t matter, you know how it’s made, it’s not even such a huge deal to replace the switch.
A hall effect sensor is just solid state, the only moving component is the thing you’re measuring. I personally stick a magnet on the cradle of my fixtures and when it’s engaged, the magnet activates a hall-effect sensor on the pogo-pin PCB below.
I know some people that have done wacky things like routing power to the pogo pins through a mechanical switch to delay it until all pins engaged and it was fine for >1000pcs. I also know someone who used a mechanical switch in their factory test fixture and it forced them to fly to China at a moment’s notice because the fixture just stopped working one day (though that was probably a series of poor decisions rather than just the one).
If you’re handing the fixture off to a manufacturer and it takes you hours to get someone there to troubleshoot things then small reliability decisions start having big impacts.