Comparing mobile devices to desktop PCs that have had decades of evolution, both in hardware and software is somewhat strange, no matter what Android marketing types want you to believe.
Do you remember what PC apps were like when a "powerful desktop computer" had in the neighborhood of 64 megabytes of RAM? That's how much each Android app gets.
Oh, I do indeed.
My first desktop PC has about 1 Meg of ram, of which only about three quarters could be used., and it had a gargantuan hard disk, with an unbelievable 107 Meg.
My feeling is that in the Android world, 'the market' in the true capitalist sense is deciding where apps get created and where not, and with so many android things being phones, little demand yet for printing or PDF output. The market can do very well without catering at all for a minority.
As tablets grow in use, and people start to need printouts of boarding cards, proofs of purchase, etc, the demand will come, and it will be worthwhile someone meeting that demand. However, the way the market works will mean that PDF output, if it comes, will be by a printing app, not built in as part of every app that needs PDF output.
Just my opinion.