Even if they have components on them, that's only $1-$2 extra per board (depending on the components), JLCPCB will assemble all the common components (resistors, capacitors, some more exotic ones) for very cheap, and you can solder the rest yourself. Their PCB assembly saves so much time, I don't want to waste half an hour soldering 20 0805 resistors to save $0.30 any more.

JLCPCB assembly services are so cheap as long as you don't use components marked as extended!

I don't solder passive components anymore and now mostly use 0402 (that i am not able to solder reliably) instead of the bigger 0805. If you value your time and don't derive pleasure from soldering passive components, try the assembly services!