I would say it's hugely more difficult! 10 X more..... and generally not practical or economical outside of specialist facilities ie a manufacturer or specialist repair centre handling 100's of repairs a week ie not hi fi gear. SMD resistors caps, transistors, op amps etc yeah sure no problem easy peasy but BGA's etc nah... the gear needed is too expensive and specialised and there is far too much risk of failure in the process. The dealing with the BGA soldering tech and it's reworking etc becomes the specialist task in itself, not the electronics.
If you are fixing 100 a week of the same thing, have all the hot air and infra red gear, pre heating oven etc etc (£ many thousands for decent gear), have bulk quantities of the components being reworked etc and can laugh at 1-2 in 10 not working after you've gone to all that time and trouble, 'cos you've got loads left to make your profit on, then yeah... but we're talking a big manufacturer or say the Sony/Apple/Samsung South East UK regional repair centre etc...
Oh and nothing anyone has to say about "some bloke fixes mobile phones with BGA's OK" changes any of what I said!)