why does anyone get a datajack implanted if trodes are just as good and a lot cheaper (both nuyen and essence)?
The incentive of using a datajack is now (besides the reasons I already listed in my previous post) is that it provide you with a point of noise reduction (like Hobbes said) which mechanically mean you get to keep your wireless bonuses in spam or static zones where perhaps you would lose it otherwise and you take one less dice penalty when remote controlling your car or when hacking a device out on the grids - but also when performing other matrix actions, such as searching the matrix for intel/legwork.
...I'm not sure if, canonically, you can hotsim with 'trodes. I would disallow that, personally.
In earlier editions you connected your cyberdeck with a fiber optic cable to the junction box or device etc and then you also connected it to its user either via an electrode net that slips over the head (which gave you limitations but was more safe - the way of cowards, aka 'tortoises'), or with direct cybernetic interface through a datajack (which you could say gave you the hot-sim equivalent we have today - the only way to fly).
In 5th edition the matrix is wireless (that transition already started in the 4th edition) and there is no longer any real difference between VR by using DNI from wearing trodes or from implanting a datajack, a control rig, a commlink or a cyberdeck (or a cyberjack that came in the next edition).
Instead now you access the matrix via AR (the way of cowards - aka 'tortoises') or via cold-sim VR (the 'normal' way) or via hot-sim VR (the only way to fly).
Do civilians care about one point of noise reduction?
Do mundane civilians care about 0.1 essence reduction...?
And most datajacks that wageslaves have were probably payed for by their company anyway.... ;-)