Why not?

The foam thing that rests on your face is personalised. Some reviews mentioned having to do scans of your face with an iPhone before purchasing.

That’s an idealistic sentiment to have that is unfortunately not representative of our current society at all.

Apple’s stock price would disagree with you there

All parametric modeling or CAD software is going to have a pretty steep learning curve

I disagree a little bit. I feel like I learnt maybe 10% of fusion 360 several years back and it’s been enough for me to design everything I’ve needed, whilst learning about other features gradually as necessary.

Op should just bite the bullet and get onto some parametric cad software.

I don’t think a phone counts as that since it’s not something that’s expected to be regularly subject to water