I think there is little risk of GA IFR pilots losing their hand flying skills.
If every airfield had an ILS then it might be a problem
The airliner world, from what I know of it, is different. I am sure the vast majority of flights within Europe (not Greece etc) can be flown fully automatic, down to ~ 100ft and actually most of the ones to major airports can be done with autoland.
GA is very different.
I strongly recommend using the AP for all real flight, and then practicing hand flying in IMC when nobody is watching you. A properly planned IFR GA flight will most likely spend so little time in IMC it won't be worth logging the instrument time.