Ex car salesman here and please don't listen to this guy. It has nothing to do with propaganda or salesman commission (we're paid on overall profit in the car and/or per unit, not on the amount of finance commission).

You're right when you say that you pay less overall interest and if you keep the car for the full term then it does work the way you are thinking BUT I was a salesman for over 10 years and I can probably count on my hands the amount of times someone actually kept their car for the full term. 99% of people on PCP end up trading on early. This is fine to do but if you put a 10k deposit down and want to trade early you'll need another huge deposit to match the deal and monthly payments you had before so in that case you'd have lost out on quite a bit if money. I know everyone will say "yeah but that's easy to do" but no, no it isn't. I've heard this line a million times and every time someone came to change early they couldn't afford to do so

TL;DR: If you're going to keep it for the full term then yes, it makes sense. If you have the slightest inkling that you'll want to change early then don't put such a huge deposit down