There are ways regulation could deal with this, though, such as making airlines state the up-front price including a large cabin bag, even if you can still go on to remove that option and thus pay less. Or to require them to state three prices up front on each search (you could easily fit that) with standard symbols/colours, i.e. minimal baggage, cabin baggage and one 23kg* checked bag, again even if they offer the option to choose a lighter bag for less.
The key is removing the price obfuscation. If customers genuinely want the complexity of a la carte pricing, fine. But it is mostly deliberately obfuscatory, i.e. you're drawn in by that cheap headline fare and then find that the 99p flight costs £150 by the time you've got a bag in the hold and a full size cabin bag for your large laptop and SLR camera.
But as I've said before (and is almost also relevant to the thread I created about differences in what "normals" and enthusiasts prefer) there's a feeling among expert passengers (whether enthusiasts or not) that is similar to the whole MoneySavingExpert culture, i.e. a fairly large body of people who specifically enjoy getting the best value out of complex and obfuscatory pricing systems at the cost of those who don't manage that, and often a fair bit of condescension towards those people who don't. And those people shout quite loudly, because they're all over X and various other influencer platforms, and thus affect airline publicity. So simpler (actually simpler, not LNER simpler*) models are often made to make the airline look bad even if for most customers they're not.
* It would be interesting to see what the influencer reaction to the genuine simplification low costs initially brought in would have been (before the nickel-and-diming kicked in) - one set of fares, one set of conditions, single fare pricing, all fares semi-flex** - I am not sure it would be as positive as we might think? Freddie Laker's Skytrain was I think in receipt of a lot of criticism and that was even simpler again, operating fixed walk-up fares and not demand pricing...
** I can genuinely see people shouting "why should I have to pay for a semi flexible fare when I'm OK with fixed" - yet that is the low cost model - all fares are changeable for a fixed fee plus fare difference, there aren't multiple levels of flexibility in most cases. This is the model that led to the Advance fare on the railway.