Heritages don't have the typical +2 to one or +1 twice to ability scores. The +1 found in backgrounds is not the same. So does this mean LU characters typically have lower ability scores that 5E characters?
Note that you start out the game with at least two expertise dice in various things (skill specialties) and possibly more due to heritage, culture, class, and high Int. So while your stats might be lower, you're going to get plenty of bonuses.
You can also get+1 to a score when you upgrade a Stronghold to Grade 3 and an additional +2 when you upgrade to Grade 6 (along with increasing your maximum ability score by 2). Even if you didn't want a stronghold you could just spend the same amount of gold training, tithing, funding guilds, etc and get the same benefit if your DM will allow it.