Originally Posted by Badger6

That's an interesting question. Consider this, the single heaviest sub-assembly of most bicycles is the wheelset. I recently bought a gravel bike, a mid range offering with carbon frame, 1x Di2 shifting, and a very heavy (2.340g total) wheelset. For 1400€, I bought a new wheelset that in total weighs 1.560g. The bike is hugely more enjoyable to ride. To get a similar wheelset specified on a bike in that model range, I'd have had to buy an S-Works level bike at more than 10000€

Often times for a even several hundred Euros, one can get a lighter wheelset that wouldn't seem like an absurd purchase for an entry level bike, and if one is willing to get up in the 1000-1200€ range you can get massively lighter wheelsets. Upgrading a whole bike would invariably cost much more, and the wheelset unless you're willing to buy an 8000-10000€ bicycle would likely not be as large of an improvement as a mid-range aftermarket wheelset.