You can go round and round on the internet until you disappear into one of your own orifices and still not have a definitive answer on things like engine oils, people have their own strongly held beliefs on such stuff. Use a good quality oil or better quality oil if you want, a very good 0w-20 oil should/might be better than a good quality 5w-30 and it is so the other way round, a very good quality 5w-30 should/might be better than a good quality 0w-20 - BUT - the differences might be small or very small. It may also depend on if you expect still to be using the engine and car in x-years time or you are only keeping the car for a short(er) number of years. The oil has to suit the circumstances, the engine, it's use and the conditions of use. Following what VW wants will meet VW requirements and that is fine, or you may want or think you need more which is fine, it is your car, time and money. VW do not care much about your engine once it is out of their warranty they would prefer to sell you either a new car or as much servicing and repair of your existing car as they can get as they can make plenty out of parts - but not out of oil, unless you buy it with VW labels on. Generally any 0w grade oil will be a good oil just to meet the 0W grade but to meet the 5w grade takes a good oil too so it is up to you which keeps you more content. Unless you do double oil changes and oil analyses over a period of time with two oils to compare it would be difficult to judge or confirm results. Personally I would use a very good oil of whichever grade you prefer. As you know if you want you can be overloaded with information and opinions and beliefs I can point you to loads of information none of it directs relates to a 2023 Fabia in Greece though, so just buy good quality, or better, engine oil and do timely, thorough* oil changes. (*this is not sucking out cold engine oil to me but fully draining out warm (hot) engine oil)