The difference is that in the US they have one "cheap" level below standard fares. What Finnair does and AFKL trials is having two levels - light and basic. That is too much imho, as the difference between the two becomes negligible and at that point they're only used to hide the real price.

I learned to tolerate one level that needs to be skipped but when I encounter airlines where I need to go up two levels, I just end up booking elsewhere. The lack of price transparency is just too much for me. Some OW airlines even do this in business (AY, QR) so I learned to just ignore them in whatever search engine I'm using since the actual price is likely to be much higher and therefore the offer I'm seeing is just a random number.

Similarly in cause of shorthaul Y, I will always go for LO, A3, TP and of course AFKL over LHG, because with those airlines I know that the price I'm seeing is more or less final (status gives me all the perks I need), whereas in case of LHG I have to go to their website and go three steps into the booking process to figure out what the actual price is.