IMO It's not done because unless you legislate this stuff private companies are not going to something that doesn't have a reasonable return on investment.
Basically there's no money in it.
And I bet the airline isn't paying for squat when it comes to search & rescue fees, that'll all be coming out of the taxpayer's pocket I bet.
woo capitalism. .
I bet if you enforced a €10,000,000 daily file for every day the plane's not found, then you'd see so many tracking equipment blisters and antenna spikes on a get it would look like a flying hedgehog.